/* ============================================
   NOCAP ACADEMY — topic.css
   Styles for all topic pages.
   Reusable across topics 1-10.
============================================ */

/* ---- PAGE ---- */
.topic-body {
  min-height: 100vh;
  background: #F1F5F9;
}

/* ---- TOPBAR (reused from dashboard) ---- */
.topbar {
  background: #0F172A;
  border-bottom: 0.5px solid rgba(255,255,255,0.08);
  position: sticky;
  top: 0;
  z-index: 100;
}
.topbar-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.topbar-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-size: 15px;
  font-weight: 500;
}
.topbar-student {
  display: flex;
  align-items: center;
  gap: 14px;
}
.student-info { text-align: right; }
.student-name { font-size: 13px; font-weight: 500; color: #fff; }
.student-meta { font-size: 11px; color: #64748B; }
.btn-signout {
  background: rgba(255,255,255,0.06);
  color: #E2E8F0;
  border: 1px solid rgba(255,255,255,0.18);
  padding: 7px 14px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.01em;
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
  transition: background 0.2s, color 0.2s, border-color 0.2s;
}
.btn-signout:hover { background: rgba(255,255,255,0.14); color: #fff; border-color: rgba(255,255,255,0.38); }

/* ---- TOPIC HEADER ---- */
.topic-header {
  background: #0F172A;
  border-bottom: 0.5px solid rgba(255,255,255,0.08);
  padding: 24px 0;
}
.topic-header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
}
.topic-eyebrow {
  font-size: 11px;
  color: #6366F1;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 6px;
}
.topic-title {
  font-size: 22px;
  font-weight: 500;
  color: #fff;
  margin-bottom: 6px;
}
.topic-subtopics-list {
  font-size: 13px;
  color: #64748B;
}
.topic-header-right { min-width: 160px; text-align: right; }
.topic-progress-label { font-size: 11px; color: #64748B; margin-bottom: 6px; }
.topic-progress-bar {
  width: 160px;
  height: 4px;
  background: rgba(255,255,255,0.1);
  border-radius: 2px;
  overflow: hidden;
  margin-bottom: 4px;
  margin-left: auto;
}
.topic-progress-fill {
  height: 100%;
  background: #6366F1;
  border-radius: 2px;
  transition: width 0.8s ease;
}
.topic-progress-pct {
  font-size: 12px;
  color: #94A3B8;
  font-family: 'DM Mono', monospace;
}

/* ---- TAB BAR ---- */
.tab-bar {
  background: #fff;
  border-bottom: 0.5px solid #E2E8F0;
  position: sticky;
  top: 60px;
  z-index: 90;
}
.tab-bar-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  gap: 0;
}
.tab {
  background: none;
  border: none;
  padding: 16px 20px;
  font-size: 14px;
  font-family: 'DM Sans', sans-serif;
  color: #64748B;
  cursor: pointer;
  border-bottom: 2px solid transparent;
  transition: color 0.2s, border-color 0.2s;
  display: flex;
  align-items: center;
  gap: 6px;
}
.tab:hover { color: #0F172A; }
.tab.active {
  color: #6366F1;
  border-bottom-color: #6366F1;
  font-weight: 500;
}
.tab.locked { opacity: 0.5; cursor: not-allowed; }
.lock-icon { font-size: 12px; }

/* ---- TAB PANELS ---- */
.tab-content {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px 60px;
}
.tab-panel { display: none; padding-top: 32px; }
.tab-panel.active { display: block; }

/* ---- SUBTOPIC NAV ---- */
.subtopic-nav {
  margin-bottom: 32px;
}
.subtopic-nav-inner {
  display: flex;
  align-items: center;
  gap: 0;
  flex-wrap: wrap;
  gap: 8px;
}
.subtopic-item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: #94A3B8;
  cursor: pointer;
  padding: 6px 12px;
  border-radius: 20px;
  border: 0.5px solid #E2E8F0;
  background: #fff;
  transition: all 0.2s;
}
.subtopic-item.active {
  color: #6366F1;
  border-color: #6366F1;
  background: #EEF2FF;
}
.subtopic-item.locked {
  opacity: 0.4;
  cursor: not-allowed;
}
.subtopic-item.complete {
  color: #166534;
  border-color: #86EFAC;
  background: #DCFCE7;
}
.subtopic-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: currentColor;
  flex-shrink: 0;
}
.subtopic-connector {
  width: 20px;
  height: 1px;
  background: #E2E8F0;
  flex-shrink: 0;
}

/* ---- LESSON AREA ---- */
.lesson-area { position: relative; }
.lesson-screen { display: none; }
.lesson-screen.active { display: block; }

.lesson-inner {
  max-width: 720px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.lesson-step-tag {
  font-size: 11px;
  font-weight: 500;
  color: #6366F1;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.lesson-title {
  font-size: 26px;
  font-weight: 500;
  color: #0F172A;
  line-height: 1.3;
}
.lesson-body {
  font-size: 15px;
  color: #475569;
  line-height: 1.8;
}

/* ---- TRANSISTOR INTERACTIVE ---- */
.transistor-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}
.transistor-label-top {
  font-size: 13px;
  color: #94A3B8;
  text-align: center;
}

/* Circuit */
.circuit-container {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  padding: 20px 0;
  flex-wrap: wrap;
  gap: 8px;
}

/* Power source */
.circuit-power {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}
.power-symbol {
  width: 44px;
  height: 44px;
  background: #F1F5F9;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  border: 0.5px solid #E2E8F0;
}
.power-label { font-size: 11px; color: #94A3B8; }

/* Wires */
.wire {
  height: 3px;
  width: 40px;
  background: #CBD5E1;
  border-radius: 2px;
  transition: background 0.4s ease;
  flex-shrink: 0;
}
.wire.on { background: #6366F1; box-shadow: 0 0 8px rgba(99,102,241,0.4); }

/* Switch */
.switch-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
}
.circuit-switch {
  background: none;
  border: none;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 8px;
  border-radius: 10px;
  transition: background 0.2s;
}
.circuit-switch:hover { background: #F1F5F9; }

.switch-track {
  width: 52px;
  height: 28px;
  background: #E2E8F0;
  border-radius: 14px;
  position: relative;
  transition: background 0.3s ease;
}
.switch-track.on { background: #6366F1; }
.switch-thumb {
  position: absolute;
  top: 4px;
  left: 4px;
  width: 20px;
  height: 20px;
  background: #fff;
  border-radius: 50%;
  transition: transform 0.3s ease;
  box-shadow: 0 1px 4px rgba(0,0,0,0.15);
}
.switch-track.on .switch-thumb { transform: translateX(24px); }
.switch-label {
  font-size: 11px;
  font-weight: 500;
  color: #94A3B8;
  font-family: 'DM Mono', monospace;
  transition: color 0.3s;
}
.switch-label.on { color: #6366F1; }

/* Bulb */
.bulb-wrap {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
}
.bulb {
  display: flex;
  flex-direction: column;
  align-items: center;
  position: relative;
  z-index: 1;
}
.bulb-glass {
  width: 40px;
  height: 48px;
  background: #F1F5F9;
  border-radius: 50% 50% 30% 30%;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 0.5px solid #E2E8F0;
  transition: background 0.4s ease, border-color 0.4s;
  position: relative;
  overflow: hidden;
}
.bulb-glass.on {
  background: #FEF3C7;
  border-color: #F59E0B;
}
.bulb-filament {
  width: 14px;
  height: 18px;
  border: 2px solid #CBD5E1;
  border-radius: 2px;
  transition: border-color 0.4s;
}
.bulb-glass.on .bulb-filament { border-color: #F59E0B; }
.bulb-base {
  width: 24px;
  height: 10px;
  background: #CBD5E1;
  border-radius: 0 0 4px 4px;
  transition: background 0.4s;
}
.bulb-glass.on + .bulb-base { background: #F59E0B; }
.bulb-glow {
  position: absolute;
  width: 70px;
  height: 70px;
  border-radius: 50%;
  background: rgba(245,158,11,0);
  top: 50%;
  left: 50%;
  transform: translate(-50%, -60%);
  transition: background 0.4s ease;
  pointer-events: none;
}
.bulb-glow.on {
  background: rgba(245,158,11,0.2);
  box-shadow: 0 0 30px rgba(245,158,11,0.3);
}

/* Binary display */
.binary-display {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}
.binary-bit {
  font-size: 64px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  color: #CBD5E1;
  line-height: 1;
  transition: color 0.3s ease, transform 0.2s ease;
}
.binary-bit.on {
  color: #6366F1;
  transform: scale(1.08);
}
.binary-state-label {
  font-size: 14px;
  font-weight: 500;
  color: #64748B;
  transition: color 0.3s;
}
.binary-state-label.on { color: #6366F1; }
.binary-explanation {
  font-size: 13px;
  color: #94A3B8;
  line-height: 1.6;
  max-width: 320px;
}

/* ---- KEY TERMS ---- */
.key-terms {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 12px;
  padding: 20px;
}
.key-term-title {
  font-size: 11px;
  font-weight: 500;
  color: #6366F1;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 14px;
}
.key-terms-grid {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.key-term {
  display: flex;
  gap: 12px;
  align-items: flex-start;
}
.key-term-word {
  font-size: 13px;
  font-weight: 500;
  color: #0F172A;
  min-width: 90px;
  font-family: 'DM Mono', monospace;
}
.key-term-def {
  font-size: 13px;
  color: #64748B;
  line-height: 1.6;
}

/* ---- LESSON FACT ---- */
.lesson-fact {
  background: #0F172A;
  border-radius: 10px;
  padding: 16px 20px;
  font-size: 14px;
  color: #94A3B8;
  line-height: 1.7;
  text-align: center;
}
.lesson-fact strong { color: #F59E0B; }

/* ---- DIVISION DEMO ---- */
.conversion-demo {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
}
.demo-label {
  font-size: 12px;
  color: #94A3B8;
  margin-bottom: 16px;
}
.division-wrap { margin-bottom: 20px; }
.division-title {
  font-size: 15px;
  font-weight: 500;
  color: #0F172A;
  margin-bottom: 14px;
}
.division-steps {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-family: 'DM Mono', monospace;
  font-size: 14px;
}
.division-step {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 12px;
  background: #F8FAFC;
  border-radius: 6px;
  border: 0.5px solid #E2E8F0;
  opacity: 0;
  transform: translateX(-12px);
  transition: opacity 0.3s ease, transform 0.3s ease;
  flex-wrap: wrap;
  gap: 8px;
}
.division-step.visible {
  opacity: 1;
  transform: translateX(0);
}
.div-calculation { color: #475569; }
.div-equals { color: #94A3B8; }
.div-quotient { color: #0F172A; font-weight: 500; }
.div-remainder {
  background: #EEF2FF;
  color: #4338CA;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 12px;
}
.div-remainder-label { font-size: 11px; color: #94A3B8; }
.division-result {
  margin-top: 16px;
  padding: 12px 16px;
  background: #0F172A;
  border-radius: 8px;
  font-family: 'DM Mono', monospace;
  font-size: 14px;
  color: #94A3B8;
  display: none;
}
.division-result.visible { display: block; }
.division-result strong { color: #F59E0B; }

.demo-controls {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}
.btn-demo {
  background: #6366F1;
  color: #fff;
  border: none;
  padding: 10px 18px;
  border-radius: 6px;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
  transition: background 0.2s;
}
.btn-demo:hover { background: #4F46E5; }
.btn-demo:disabled { background: #CBD5E1; cursor: not-allowed; }
.btn-demo-reset {
  background: transparent;
  color: #64748B;
  border: 0.5px solid #E2E8F0;
  padding: 10px 18px;
  border-radius: 6px;
  font-size: 13px;
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
  transition: border-color 0.2s, color 0.2s;
}
.btn-demo-reset:hover { border-color: #94A3B8; color: #0F172A; }

/* ---- TRY IT ---- */
.tryit-wrap {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.tryit-label {
  font-size: 13px;
  font-weight: 500;
  color: #0F172A;
}
.tryit-question {
  font-size: 18px;
  font-weight: 500;
  color: #0F172A;
}
.tryit-number {
  color: #6366F1;
  font-family: 'DM Mono', monospace;
}
.tryit-input-row {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}
.tryit-input {
  flex: 1;
  min-width: 140px;
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 8px;
  padding: 11px 14px;
  font-size: 16px;
  color: #0F172A;
  font-family: 'DM Sans', sans-serif;
  outline: none;
  transition: border-color 0.2s;
}
.tryit-input.mono { font-family: 'DM Mono', monospace; letter-spacing: 0.1em; }
.tryit-input:focus { border-color: #6366F1; }
.tryit-input.correct { border-color: #22C55E; background: #F0FDF4; }
.tryit-input.incorrect { border-color: #EF4444; background: #FEF2F2; }
.btn-check {
  background: #0F172A;
  color: #fff;
  border: none;
  padding: 11px 20px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
  transition: background 0.2s;
  white-space: nowrap;
}
.btn-check:hover { background: #1E293B; }
.tryit-feedback {
  font-size: 14px;
  font-weight: 500;
  min-height: 20px;
  transition: all 0.2s;
}
.tryit-feedback.correct { color: #16A34A; }
.tryit-feedback.incorrect { color: #DC2626; }
.tryit-hint { font-size: 12px; color: #94A3B8; line-height: 1.6; }

/* ---- POWERS TABLE ---- */
.powers-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.powers-label { font-size: 13px; color: #64748B; }
.powers-table {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}
.power-cell {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  cursor: pointer;
  transition: transform 0.15s;
}
.power-cell:hover { transform: scale(1.05); }
.power-exp {
  font-size: 10px;
  color: #94A3B8;
  font-family: 'DM Mono', monospace;
}
.power-val {
  width: 44px;
  height: 44px;
  background: #F1F5F9;
  border: 0.5px solid #E2E8F0;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 500;
  color: #475569;
  font-family: 'DM Mono', monospace;
  transition: background 0.2s, color 0.2s, border-color 0.2s;
}
.power-val.selected {
  background: #6366F1;
  color: #fff;
  border-color: #6366F1;
}
.power-bit {
  font-size: 16px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  color: #CBD5E1;
}
.power-bit.is-one { color: #6366F1; }
.powers-total-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
}
.powers-total-label { font-size: 13px; color: #64748B; }
.powers-total {
  font-size: 28px;
  font-weight: 500;
  color: #0F172A;
  font-family: 'DM Mono', monospace;
  transition: color 0.2s;
}

/* ---- LESSON NAV ---- */
.lesson-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 8px;
  border-top: 0.5px solid #E2E8F0;
}
.btn-lesson-back,
.btn-lesson-next {
  background: none;
  border: 0.5px solid #E2E8F0;
  color: #64748B;
  padding: 10px 20px;
  border-radius: 8px;
  font-size: 14px;
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
  transition: all 0.2s;
}
.btn-lesson-back:hover,
.btn-lesson-next:hover {
  border-color: #6366F1;
  color: #6366F1;
}
.btn-lesson-back:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}
.btn-lesson-next {
  background: #6366F1;
  border-color: #6366F1;
  color: #fff;
}
.btn-lesson-next:hover { background: #4F46E5; border-color: #4F46E5; color: #fff; }
.btn-complete {
  background: #16A34A !important;
  border-color: #16A34A !important;
}
.btn-complete:hover { background: #15803D !important; }
.btn-complete:disabled {
  background: #CBD5E1 !important;
  border-color: #CBD5E1 !important;
  color: #94A3B8 !important;
  cursor: not-allowed !important;
}
.lesson-dots {
  display: flex;
  gap: 6px;
}
.lesson-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #E2E8F0;
  transition: background 0.2s;
}
.lesson-dot.active { background: #6366F1; }

/* ---- LOCKED PANEL ---- */
.locked-panel {
  text-align: center;
  padding: 60px 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}
.locked-icon { font-size: 40px; }
.locked-title {
  font-size: 18px;
  font-weight: 500;
  color: #0F172A;
}
.locked-body {
  font-size: 14px;
  color: #64748B;
  max-width: 320px;
  line-height: 1.6;
}
.btn-go-learn {
  background: #6366F1;
  color: #fff;
  border: none;
  padding: 12px 24px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
  margin-top: 8px;
  transition: background 0.2s;
}
.btn-go-learn:hover { background: #4F46E5; }

/* ---- RESOURCES ---- */
.resource-card {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 16px;
}
.resource-card-title {
  font-size: 13px;
  font-weight: 500;
  color: #0F172A;
  margin-bottom: 14px;
}
.resource-table-wrap { overflow-x: auto; }
.resource-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}
.resource-table th {
  background: #F8FAFC;
  color: #64748B;
  font-weight: 500;
  padding: 8px 12px;
  border: 0.5px solid #E2E8F0;
  text-align: center;
  font-family: 'DM Mono', monospace;
}
.resource-table td {
  padding: 8px 12px;
  border: 0.5px solid #E2E8F0;
  text-align: center;
  color: #475569;
  font-family: 'DM Mono', monospace;
}
.resource-table td:first-child {
  font-weight: 500;
  color: #0F172A;
  text-align: left;
  font-family: 'DM Sans', sans-serif;
}
.method-list { display: flex; flex-direction: column; gap: 12px; }
.method-item {
  padding: 12px;
  background: #F8FAFC;
  border-radius: 8px;
  border: 0.5px solid #E2E8F0;
}
.method-name {
  font-size: 13px;
  font-weight: 500;
  color: #0F172A;
  margin-bottom: 4px;
  font-family: 'DM Mono', monospace;
}
.method-desc { font-size: 13px; color: #64748B; line-height: 1.6; }

/* ---- DESKTOP ---- */
@media (min-width: 768px) {
  .topic-title { font-size: 28px; }
  .lesson-title { font-size: 30px; }
  .key-terms-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
  }
  .powers-table { flex-wrap: nowrap; }
}


/* ---- HEXADECIMAL LESSON ---- */

/* Comparison grid */
.hex-comparison {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.hex-comp-label {
  font-size: 12px;
  color: #94A3B8;
}
.hex-comp-grid {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}
.hex-comp-card {
  flex: 1;
  min-width: 100px;
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 10px;
  padding: 16px;
  text-align: center;
}
.hex-comp-card.highlight {
  background: #EEF2FF;
  border-color: #6366F1;
}
.hex-comp-system {
  font-size: 11px;
  color: #94A3B8;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 8px;
}
.hex-comp-value {
  font-size: 22px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  margin-bottom: 6px;
}
.denary-val { color: #475569; }
.binary-val { color: #94A3B8; font-size: 16px; }
.hex-val    { color: #6366F1; }
.hex-comp-base {
  font-size: 11px;
  color: #94A3B8;
}
.hex-comp-arrow {
  font-size: 18px;
  color: #CBD5E1;
  flex-shrink: 0;
}
.hex-comp-note {
  font-size: 13px;
  color: #64748B;
  line-height: 1.6;
  padding-top: 12px;
  border-top: 0.5px solid #E2E8F0;
}

/* Hex input grid */
.hex-table-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.hex-table-label {
  font-size: 13px;
  color: #64748B;
  line-height: 1.6;
}
.hex-input-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}
.hex-cell {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}
.hex-cell-denary {
  font-size: 12px;
  color: #94A3B8;
  font-family: 'DM Mono', monospace;
}
.hex-cell-input {
  width: 100%;
  max-width: 56px;
  height: 44px;
  text-align: center;
  font-size: 16px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 8px;
  color: #0F172A;
  outline: none;
  transition: border-color 0.2s, background 0.2s;
  text-transform: uppercase;
}
.hex-cell-input:focus {
  border-color: #6366F1;
  background: #fff;
}
.hex-cell-input.correct {
  border-color: #22C55E;
  background: #F0FDF4;
  color: #16A34A;
}
.hex-cell-input.incorrect {
  border-color: #EF4444;
  background: #FEF2F2;
}
.hex-cell-input[readonly] {
  background: #F0FDF4;
  border-color: #22C55E;
  color: #16A34A;
  cursor: default;
}
.hex-table-feedback {
  font-size: 13px;
  font-weight: 500;
  min-height: 20px;
}
.hex-table-feedback.correct { color: #16A34A; }
.hex-table-feedback.incorrect { color: #DC2626; }

/* Nibble display */
.hex-nibble-wrap {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.hex-nibble-label {
  font-size: 13px;
  color: #64748B;
  line-height: 1.6;
}
.hex-nibble-controls {
  display: flex;
  gap: 12px;
  align-items: center;
}
.hex-select {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 8px;
  padding: 10px 14px;
  font-size: 14px;
  font-family: 'DM Sans', sans-serif;
  color: #0F172A;
  outline: none;
  cursor: pointer;
  transition: border-color 0.2s;
}
.hex-select:focus { border-color: #6366F1; }
.hex-nibble-display {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}
.nibble-bits {
  display: flex;
  gap: 8px;
}
.nibble-bit {
  width: 52px;
  height: 52px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  border: 0.5px solid #E2E8F0;
  background: #fff;
  transition: all 0.3s ease;
}
.nibble-bit.empty {
  color: #CBD5E1;
  background: #F8FAFC;
}
.nibble-bit.is-one {
  background: #6366F1;
  border-color: #6366F1;
  color: #fff;
}
.nibble-bit.is-zero {
  background: #F1F5F9;
  border-color: #E2E8F0;
  color: #94A3B8;
}
.nibble-labels {
  display: flex;
  gap: 8px;
}
.nibble-labels span {
  width: 52px;
  text-align: center;
  font-size: 11px;
  color: #94A3B8;
  font-family: 'DM Mono', monospace;
}
.nibble-result {
  font-size: 14px;
  color: #64748B;
  text-align: center;
  min-height: 22px;
  transition: all 0.2s;
}
.nibble-result strong { color: #6366F1; }

@media (min-width: 768px) {
  .hex-input-grid {
    grid-template-columns: repeat(8, 1fr);
  }
}


/* ---- LESSON 5 — HEX CONVERSIONS ---- */

.conv-selector {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 12px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.conv-selector-label {
  font-size: 12px;
  color: #94A3B8;
}
.conv-btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.conv-btn {
  background: #F1F5F9;
  border: 0.5px solid #E2E8F0;
  color: #64748B;
  padding: 9px 16px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
  transition: all 0.2s;
}
.conv-btn:hover {
  border-color: #6366F1;
  color: #6366F1;
}
.conv-btn.active {
  background: #6366F1;
  border-color: #6366F1;
  color: #fff;
}

/* Conversion panels */
.conv-panel {
  display: none;
  flex-direction: column;
  gap: 20px;
}
.conv-panel.active {
  display: flex;
}

/* H2D visual */
.h2d-visual {
  margin-bottom: 8px;
}
.h2d-steps {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 12px;
}
.h2d-step {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  background: #F8FAFC;
  border-radius: 8px;
  border: 0.5px solid #E2E8F0;
  font-family: 'DM Mono', monospace;
  font-size: 14px;
  opacity: 0;
  transform: translateX(-12px);
  transition: opacity 0.3s ease, transform 0.3s ease;
  flex-wrap: wrap;
  gap: 8px;
}
.h2d-step.visible {
  opacity: 1;
  transform: translateX(0);
}
.h2d-digit   { font-size: 18px; font-weight: 500; color: #6366F1; }
.h2d-times   { color: #94A3B8; }
.h2d-power   { color: #475569; }
.h2d-equals  { color: #94A3B8; }
.h2d-value   { font-weight: 500; color: #0F172A; }

/* Nibble conversion visual */
.nibble-conv-wrap {
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.nibble-conv-row {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}
.nibble-conv-digit {
  font-size: 28px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  color: #6366F1;
  min-width: 32px;
  text-align: center;
}
.nibble-conv-arrow-small {
  font-size: 16px;
  color: #CBD5E1;
}
.nibble-bits-small {
  display: flex;
  gap: 4px;
}
.nibble-bit-small {
  width: 36px;
  height: 36px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  border: 0.5px solid #E2E8F0;
  background: #F8FAFC;
  color: #CBD5E1;
  opacity: 0;
  transform: translateY(6px);
  transition: all 0.25s ease;
}
.nibble-bit-small.visible {
  opacity: 1;
  transform: translateY(0);
}
.nibble-bit-small.is-one {
  background: #6366F1;
  border-color: #6366F1;
  color: #fff;
}
.nibble-bit-small.is-zero {
  background: #F1F5F9;
  border-color: #E2E8F0;
  color: #94A3B8;
}
.nibble-conv-label {
  font-size: 12px;
  color: #94A3B8;
  font-family: 'DM Mono', monospace;
}
.nibble-conv-combined {
  font-size: 14px;
  color: #64748B;
  padding: 10px 14px;
  background: #0F172A;
  border-radius: 8px;
  font-family: 'DM Mono', monospace;
  opacity: 0;
  transition: opacity 0.4s ease;
}
.nibble-conv-combined.visible {
  opacity: 1;
}
.nibble-conv-combined strong { color: #F59E0B; }

/* Binary grouping visual */
.binary-group-wrap {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.binary-group-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
.binary-group {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}
.binary-group-bits {
  display: flex;
  gap: 3px;
}
.binary-group-bit {
  width: 32px;
  height: 32px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 15px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  border: 0.5px solid #E2E8F0;
  background: #F8FAFC;
  color: #475569;
  opacity: 0;
  transform: translateY(6px);
  transition: all 0.25s ease;
}
.binary-group-bit.visible {
  opacity: 1;
  transform: translateY(0);
}
.binary-group-bit.is-one {
  background: #EEF2FF;
  border-color: #6366F1;
  color: #6366F1;
}
.binary-group-hex {
  font-size: 18px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  color: #F59E0B;
  opacity: 0;
  transition: opacity 0.3s ease 0.3s;
}
.binary-group-hex.visible { opacity: 1; }


/* ---- LESSON 6 — BINARY ADDITION ---- */

/* Rules grid */
.rules-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.rules-label { font-size: 12px; color: #94A3B8; }
.rules-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
}
.rule-card {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 10px;
  padding: 16px;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  transition: border-color 0.2s, background 0.2s;
  text-align: center;
}
.rule-card:hover { border-color: #6366F1; }
.rule-card.highlight { border-color: rgba(99,102,241,0.3); background: #EEF2FF; }
.rule-card.revealed { border-color: #6366F1; background: #EEF2FF; }
.rule-sum {
  font-family: 'DM Mono', monospace;
  font-size: 18px;
  font-weight: 500;
  color: #0F172A;
}
.rule-equals { font-size: 14px; color: #94A3B8; }
.rule-result {
  font-family: 'DM Mono', monospace;
  font-size: 28px;
  font-weight: 500;
  color: #CBD5E1;
  transition: color 0.3s;
  min-height: 36px;
}
.rule-result.revealed { color: #6366F1; }
.rule-carry {
  font-size: 11px;
  font-weight: 500;
  color: #F59E0B;
  background: #FEF3C7;
  padding: 2px 8px;
  border-radius: 4px;
  font-family: 'DM Mono', monospace;
}
.rule-explain {
  font-size: 12px;
  color: #64748B;
  line-height: 1.5;
}
.hidden { display: none !important; }

/* Addition demo */
.addition-demo-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.addition-display {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-family: 'DM Mono', monospace;
}
.add-row {
  display: flex;
  align-items: center;
  gap: 4px;
}
.add-row-label {
  font-size: 11px;
  color: #94A3B8;
  width: 56px;
  text-align: right;
  flex-shrink: 0;
}
.add-bits {
  display: flex;
  gap: 3px;
}
.add-bit {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  font-weight: 500;
  border-radius: 6px;
  border: 0.5px solid #E2E8F0;
  background: #F8FAFC;
  color: #475569;
  transition: all 0.25s ease;
}
.add-bit.active {
  background: #6366F1;
  border-color: #6366F1;
  color: #fff;
}
.add-bit.carry-bit {
  background: #FEF3C7;
  border-color: #F59E0B;
  color: #92400E;
}
.add-bit.result-bit {
  background: #DCFCE7;
  border-color: #22C55E;
  color: #166534;
}
.add-bit.overflow-bit {
  background: #FEE2E2;
  border-color: #EF4444;
  color: #991B1B;
}
.add-divider {
  height: 1px;
  background: #E2E8F0;
  margin: 4px 0 4px 60px;
}
.addition-carry-row {
  font-size: 11px;
  color: #94A3B8;
  margin-left: 60px;
}
.addition-result-wrap {
  background: #0F172A;
  border-radius: 8px;
  padding: 12px 16px;
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 4px;
}
.addition-result-label {
  font-size: 12px;
  color: #64748B;
  font-family: 'DM Mono', monospace;
  flex-shrink: 0;
}
.addition-result {
  font-family: 'DM Mono', monospace;
  font-size: 16px;
  font-weight: 500;
  color: #F59E0B;
}

/* Binary try-it display */
.binary-tryit-display {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-family: 'DM Mono', monospace;
  margin: 4px 0;
}
.binary-tryit-row {
  display: flex;
  align-items: center;
  gap: 8px;
}
.binary-tryit-label {
  font-size: 12px;
  color: #94A3B8;
  width: 24px;
  text-align: right;
}
.binary-tryit-number {
  font-size: 18px;
  font-weight: 500;
  color: #0F172A;
  letter-spacing: 0.1em;
}
.binary-tryit-divider {
  height: 1px;
  background: #E2E8F0;
  margin-left: 32px;
}

/* Overflow section */
.overflow-wrap {
  background: #FFF7ED;
  border: 0.5px solid #FED7AA;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.overflow-title {
  font-size: 15px;
  font-weight: 500;
  color: #92400E;
}
.overflow-body {
  font-size: 14px;
  color: #78350F;
  line-height: 1.7;
}
.overflow-demo {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-family: 'DM Mono', monospace;
}
.overflow-options {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 8px;
}
.overflow-option {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 10px;
  cursor: pointer;
  transition: border-color 0.2s;
  font-family: 'DM Mono', monospace;
  font-size: 14px;
  color: #0F172A;
}
.overflow-option:hover { border-color: #6366F1; }
.overflow-option.correct { border-color: #22C55E; background: #F0FDF4; }
.overflow-option.incorrect { border-color: #EF4444; background: #FEF2F2; }
.overflow-option-label {
  font-size: 12px;
  color: #94A3B8;
  width: 16px;
}

@media (min-width: 768px) {
  .rules-grid { grid-template-columns: repeat(4, 1fr); }
}


/* ---- LESSON 7 — BINARY SHIFTS ---- */

.shift-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.shift-section-title {
  font-size: 14px;
  font-weight: 500;
  color: #0F172A;
}
.shift-effect-label {
  font-size: 13px;
  color: #64748B;
  font-family: 'DM Mono', monospace;
}
.shift-val {
  color: #6366F1;
  font-weight: 500;
}
.shift-register-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}
.shift-register {
  display: flex;
  gap: 4px;
}
.shift-bit {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 17px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  border-radius: 8px;
  border: 0.5px solid #E2E8F0;
  background: #F8FAFC;
  color: #475569;
  transition: all 0.2s ease;
}
.shift-bit.is-one {
  background: #EEF2FF;
  border-color: #6366F1;
  color: #4338CA;
}
.shift-bit.just-added {
  background: #DCFCE7;
  border-color: #22C55E;
  color: #166534;
  animation: popIn 0.3s ease;
}
.shift-bit.about-to-fall {
  background: #FEE2E2;
  border-color: #EF4444;
  color: #991B1B;
}
@keyframes popIn {
  from { transform: scale(0.7); opacity: 0; }
  to   { transform: scale(1);   opacity: 1; }
}
.shift-lost-zone {
  width: 44px;
  height: 40px;
  border-radius: 8px;
  border: 1.5px dashed #E2E8F0;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}
.lost-bit {
  font-size: 17px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  color: #EF4444;
  opacity: 0;
  transition: opacity 0.3s;
}
.lost-bit.visible { opacity: 1; }
.shift-incoming {
  width: 40px;
  height: 40px;
  border-radius: 8px;
  border: 1.5px dashed #22C55E;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 17px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  color: #22C55E;
}
.shift-controls {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}
.btn-shift {
  background: #6366F1;
  color: #fff;
  border: none;
  padding: 10px 20px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
  transition: background 0.2s;
}
.btn-shift:hover { background: #4F46E5; }
.btn-shift:disabled { background: #CBD5E1; cursor: not-allowed; }
.shift-log {
  display: flex;
  flex-direction: column;
  gap: 4px;
  max-height: 100px;
  overflow-y: auto;
}
.shift-log-entry {
  font-size: 12px;
  font-family: 'DM Mono', monospace;
  color: #64748B;
  padding: 4px 8px;
  background: #F8FAFC;
  border-radius: 4px;
  display: flex;
  gap: 8px;
  align-items: center;
}
.shift-log-entry .log-arrow { color: #6366F1; }
.shift-log-entry .log-effect { color: #22C55E; font-weight: 500; }
.shift-log-entry .log-lost { color: #EF4444; }

/* Lost bits warning */
.lost-bits-warn {
  background: #FFF7ED;
  border: 0.5px solid #FED7AA;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.warn-title {
  font-size: 14px;
  font-weight: 500;
  color: #92400E;
}
.warn-body {
  font-size: 14px;
  color: #78350F;
  line-height: 1.7;
}
.lost-demo-wrap {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.lost-denary-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: 'DM Mono', monospace;
}
.lost-denary-label { font-size: 12px; color: #94A3B8; }
.lost-denary-val {
  font-size: 20px;
  font-weight: 500;
  color: #0F172A;
  transition: color 0.3s;
}
.lost-denary-val.wrong { color: #EF4444; }
.lost-warning {
  font-size: 13px;
  font-weight: 500;
  color: #DC2626;
  min-height: 20px;
}
.shift-tryit-block {
  display: flex;
  flex-direction: column;
  gap: 10px;
}


/* ---- LESSON 8 — TWO'S COMPLEMENT ---- */

.twos-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.sign-register-wrap {
  display: flex;
  justify-content: flex-start;
}
.sign-register {
  display: flex;
  gap: 4px;
}
.sign-bit {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 17px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  border-radius: 8px;
  border: 0.5px solid #E2E8F0;
  background: #F8FAFC;
  color: #475569;
  transition: all 0.25s ease;
}
.sign-bit.is-one { background: #EEF2FF; border-color: #6366F1; color: #4338CA; }
.sign-bit.msb { cursor: pointer; border-width: 1.5px; }
.sign-bit.msb.is-zero { border-color: #22C55E; background: #F0FDF4; color: #166534; }
.sign-bit.msb.is-one  { border-color: #EF4444; background: #FEF2F2; color: #991B1B; }
.sign-bit.msb:hover { transform: scale(1.08); }
.sign-display {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.sign-indicator {
  display: flex;
  align-items: center;
  gap: 12px;
}
.sign-badge {
  font-size: 12px;
  font-weight: 500;
  padding: 4px 12px;
  border-radius: 20px;
  transition: all 0.3s;
}
.sign-badge.positive { background: #DCFCE7; color: #166534; }
.sign-badge.negative { background: #FEE2E2; color: #991B1B; }
.sign-value {
  font-size: 28px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  color: #0F172A;
  transition: color 0.3s;
}
.sign-value.negative { color: #DC2626; }
.sign-explain { font-size: 13px; color: #64748B; line-height: 1.6; }

/* Methods */
.twos-method-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.method-header {
  display: flex;
  align-items: center;
  gap: 10px;
}
.method-badge {
  font-size: 11px;
  font-weight: 500;
  background: #EEF2FF;
  color: #4338CA;
  padding: 3px 10px;
  border-radius: 20px;
}
.method-badge-2 { background: #FEF3C7; color: #92400E; }
.method-title {
  font-size: 15px;
  font-weight: 500;
  color: #0F172A;
}

/* Flip demo */
.flip-demo {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 10px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.flip-demo-label { font-size: 12px; color: #94A3B8; }
.flip-steps { display: flex; flex-direction: column; gap: 10px; }
.flip-row {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}
.flip-row-label {
  font-size: 11px;
  color: #94A3B8;
  width: 48px;
  flex-shrink: 0;
}
.flip-bits { display: flex; gap: 3px; }
.flip-bit {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 15px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  border-radius: 6px;
  border: 0.5px solid #E2E8F0;
  background: #fff;
  color: #475569;
  transition: all 0.25s ease;
}
.flip-bit.is-one { background: #EEF2FF; border-color: #6366F1; color: #4338CA; }
.flip-bit.flipped { background: #FEF3C7; border-color: #F59E0B; color: #92400E; animation: flipAnim 0.3s ease; }
.flip-bit.added  { background: #DCFCE7; border-color: #22C55E; color: #166534; }
.flip-bit.msb-neg { background: #FEE2E2; border-color: #EF4444; color: #991B1B; }
@keyframes flipAnim {
  0%   { transform: rotateY(0deg); }
  50%  { transform: rotateY(90deg); }
  100% { transform: rotateY(0deg); }
}
.flip-row-note { font-size: 12px; color: #64748B; }
.flip-result {
  background: #0F172A;
  border-radius: 8px;
  padding: 12px 16px;
  font-size: 13px;
  color: #94A3B8;
  line-height: 1.7;
  font-family: 'DM Sans', monospace;
}

/* Weight table */
.weight-demo {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 10px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.weight-table { display: flex; gap: 4px; flex-wrap: wrap; }
.weight-cell {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  cursor: pointer;
  transition: transform 0.15s;
}
.weight-cell:hover { transform: scale(1.05); }
.weight-exp { font-size: 10px; color: #94A3B8; font-family: 'DM Mono', monospace; text-align: center; }
.weight-exp.negative { color: #EF4444; }
.weight-val {
  width: 40px;
  height: 40px;
  background: #F1F5F9;
  border: 0.5px solid #E2E8F0;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  font-weight: 500;
  color: #475569;
  font-family: 'DM Mono', monospace;
  transition: all 0.2s;
}
.weight-val.selected { background: #6366F1; color: #fff; border-color: #6366F1; }
.weight-val.selected.msb-neg { background: #EF4444; border-color: #EF4444; }
.weight-bit { font-size: 16px; font-weight: 500; font-family: 'DM Mono', monospace; color: #CBD5E1; }
.weight-bit.is-one { color: #6366F1; }
.weight-bit.is-one.msb-neg { color: #EF4444; }

/* Comparison */
.comparison-wrap {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.comparison-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
.comparison-card {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 10px;
  padding: 16px;
}
.comparison-card-title {
  font-size: 12px;
  font-weight: 500;
  color: #6366F1;
  margin-bottom: 10px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.comparison-steps { display: flex; flex-direction: column; gap: 6px; }
.comp-step {
  font-size: 12px;
  font-family: 'DM Mono', monospace;
  color: #64748B;
  line-height: 1.5;
}
.comp-answer {
  font-size: 14px;
  font-weight: 500;
  color: #0F172A;
  margin-top: 6px;
  font-family: 'DM Mono', monospace;
}


/* ---- LESSON 9 — TEXT REPRESENTATION ---- */

/* Keyboard visual */
.keyboard-question-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.keyboard-visual {
  background: #1E293B;
  border-radius: 10px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  align-items: center;
}
.kb-row {
  display: flex;
  gap: 5px;
  justify-content: center;
  flex-wrap: wrap;
}
.kb-key {
  background: #334155;
  color: #E2E8F0;
  border-radius: 5px;
  font-size: 12px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 0.5px solid #475569;
  cursor: default;
  transition: background 0.15s;
  user-select: none;
}
.kb-key.wide { width: 32px; height: 32px; }
.kb-key.space { width: 160px; height: 28px; font-size: 10px; color: #64748B; }
.kb-key:hover { background: #475569; }
.keyboard-prompt {
  font-size: 15px;
  color: #0F172A;
  font-weight: 500;
  text-align: center;
}
.keyboard-options {
  display: flex;
  gap: 10px;
  justify-content: center;
  flex-wrap: wrap;
}
.kb-option {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  color: #475569;
  padding: 10px 20px;
  border-radius: 8px;
  font-size: 14px;
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
  transition: all 0.2s;
}
.kb-option:hover { border-color: #6366F1; color: #6366F1; }
.kb-option.correct { background: #DCFCE7; border-color: #22C55E; color: #166534; }
.kb-option.incorrect { background: #FEE2E2; border-color: #EF4444; color: #991B1B; }
.kb-option.disabled { pointer-events: none; opacity: 0.5; }
.keyboard-feedback {
  font-size: 14px;
  font-weight: 500;
  text-align: center;
  color: #16A34A;
  line-height: 1.6;
}

/* ASCII wrap */
.ascii-wrap {
  display: flex;
  flex-direction: column;
  gap: 24px;
}
.ascii-table-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.ascii-groups {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.ascii-group {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 8px;
  padding: 12px 16px;
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}
.ascii-group-label {
  font-size: 13px;
  font-weight: 500;
  color: #0F172A;
  font-family: 'DM Mono', monospace;
  min-width: 80px;
}
.ascii-group-range {
  font-size: 13px;
  color: #6366F1;
  font-family: 'DM Mono', monospace;
}
.ascii-group-example {
  font-size: 12px;
  color: #94A3B8;
}

/* ASCII explorer */
.ascii-explorer {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.ascii-explorer-input-row {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}
.ascii-char-input {
  width: 64px;
  height: 64px;
  text-align: center;
  font-size: 28px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 10px;
  color: #0F172A;
  outline: none;
  transition: border-color 0.2s;
}
.ascii-char-input:focus { border-color: #6366F1; }
.ascii-explorer-result {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  flex: 1;
}
.ascii-result-item {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 8px;
  padding: 10px 16px;
  text-align: center;
  min-width: 80px;
}
.ascii-result-label { font-size: 10px; color: #94A3B8; margin-bottom: 4px; text-transform: uppercase; letter-spacing: 0.05em; }
.ascii-result-val { font-size: 16px; font-weight: 500; color: #6366F1; }
.ascii-result-val.mono { font-family: 'DM Mono', monospace; font-size: 13px; }
.ascii-result-arrow { font-size: 16px; color: #CBD5E1; }

/* Name demo */
.ascii-name-demo { display: flex; flex-direction: column; gap: 12px; }
.ascii-name-input {
  width: 200px;
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 8px;
  padding: 10px 14px;
  font-size: 16px;
  font-family: 'DM Sans', sans-serif;
  color: #0F172A;
  outline: none;
  transition: border-color 0.2s;
}
.ascii-name-input:focus { border-color: #6366F1; }
.ascii-name-output {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}
.ascii-name-char {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 6px;
  padding: 6px 8px;
  min-width: 44px;
  animation: popIn 0.2s ease;
}
.ascii-name-char-letter {
  font-size: 16px;
  font-weight: 500;
  color: #0F172A;
  font-family: 'DM Mono', monospace;
}
.ascii-name-char-dec {
  font-size: 10px;
  color: #6366F1;
  font-family: 'DM Mono', monospace;
}
.ascii-name-char-bin {
  font-size: 9px;
  color: #94A3B8;
  font-family: 'DM Mono', monospace;
}

/* Unicode section */
.unicode-wrap { display: flex; flex-direction: column; gap: 16px; }
.unicode-problem {
  background: #FFF7ED;
  border: 0.5px solid #FED7AA;
  border-radius: 12px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.unicode-chars {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}
.unicode-char-card {
  background: #fff;
  border: 0.5px solid #FED7AA;
  border-radius: 8px;
  padding: 12px 16px;
  text-align: center;
  min-width: 80px;
}
.unicode-char { font-size: 28px; margin-bottom: 6px; }
.unicode-char-label { font-size: 11px; color: #64748B; margin-bottom: 4px; }
.unicode-char-ascii {
  font-size: 10px;
  color: #EF4444;
  font-weight: 500;
  background: #FEE2E2;
  padding: 2px 6px;
  border-radius: 4px;
}
.ascii-vs-unicode { background: #F8FAFC; border-radius: 12px; padding: 16px; }
.unicode-mcq {
  display: flex;
  flex-direction: column;
  gap: 8px;
  width: 100%;
}
.unicode-mcq .kb-option {
  text-align: left;
  padding: 12px 16px;
  width: 100%;
  white-space: normal;
  line-height: 1.5;
}

/* ---- SUBTOPIC COMPLETE BANNER ---- */
.subtopic-complete-banner {
  padding: 60px 20px;
  text-align: center;
}
.subtopic-banner-inner {
  max-width: 480px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}
.subtopic-banner-icon {
  width: 64px;
  height: 64px;
  background: #DCFCE7;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  color: #16A34A;
}
.subtopic-banner-title {
  font-size: 24px;
  font-weight: 500;
  color: #0F172A;
}
.subtopic-banner-body {
  font-size: 15px;
  color: #64748B;
  line-height: 1.7;
}
.btn-banner-next {
  background: #6366F1;
  color: #fff;
  border: none;
  padding: 14px 32px;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
  transition: background 0.2s;
  margin-top: 8px;
}
.btn-banner-next:hover { background: #4F46E5; }

/* Pulse animation for newly unlocked subtopic */
.subtopic-item.unlocked-pulse {
  animation: subtopicPulse 1.5s ease infinite;
  border-color: #6366F1;
  color: #6366F1;
  background: #EEF2FF;
  cursor: pointer;
}
@keyframes subtopicPulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(99,102,241,0.4); }
  50%       { box-shadow: 0 0 0 6px rgba(99,102,241,0); }
}


/* ---- LESSON 10 — SOUND REPRESENTATION ---- */

.wave-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
#wave-canvas {
  width: 100%;
  height: 140px;
  border-radius: 8px;
  background: #0F172A;
}
.wave-controls { display: flex; gap: 10px; flex-wrap: wrap; }
.wave-info {
  font-size: 13px;
  color: #64748B;
  font-family: 'DM Mono', monospace;
}
.wave-info strong { color: #6366F1; }

.sound-concept-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.sound-concept-title {
  font-size: 15px;
  font-weight: 500;
  color: #0F172A;
}
.sound-examples {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 10px;
}
.sound-example-card {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 10px;
  padding: 14px;
  text-align: center;
}
.sound-example-card.highlight {
  background: #EEF2FF;
  border-color: #6366F1;
}
.sound-example-val {
  font-size: 16px;
  font-weight: 500;
  color: #0F172A;
  font-family: 'DM Mono', monospace;
  margin-bottom: 6px;
}
.sound-example-label {
  font-size: 12px;
  font-weight: 500;
  color: #6366F1;
  margin-bottom: 4px;
}
.sound-example-desc { font-size: 11px; color: #94A3B8; }

/* Resolution visual */
.resolution-visual {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}
.res-card {
  flex: 1;
  min-width: 120px;
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 10px;
  padding: 14px;
  text-align: center;
}
.res-bits {
  font-size: 20px;
  font-weight: 500;
  color: #6366F1;
  font-family: 'DM Mono', monospace;
  margin-bottom: 4px;
}
.res-values { font-size: 12px; color: #0F172A; margin-bottom: 4px; font-weight: 500; }
.res-desc { font-size: 11px; color: #94A3B8; }

/* Storage units */
.storage-units-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

/* File size walkthrough */
.filesize-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.filesize-example {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 10px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.filesize-steps { display: flex; flex-direction: column; gap: 8px; }
.filesize-step {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 12px 14px;
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 8px;
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.3s ease, transform 0.3s ease;
}
.filesize-step.visible {
  opacity: 1;
  transform: translateY(0);
}
.filesize-step-num {
  width: 24px;
  height: 24px;
  background: #6366F1;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  font-weight: 500;
  color: #fff;
  flex-shrink: 0;
}
.filesize-step-content { flex: 1; }
.filesize-step-formula {
  font-family: 'DM Mono', monospace;
  font-size: 13px;
  color: #475569;
  margin-bottom: 4px;
}
.filesize-step-result {
  font-family: 'DM Mono', monospace;
  font-size: 15px;
  font-weight: 500;
  color: #6366F1;
}
.filesize-step-unit {
  font-size: 11px;
  color: #94A3B8;
  margin-top: 2px;
}


/* ---- LESSON 11 — IMAGE REPRESENTATION ---- */

.pixel-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.pixel-demo-grid {
  display: flex;
  gap: 20px;
  align-items: flex-start;
  flex-wrap: wrap;
}
.pixel-image-side {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}
#pixel-canvas {
  border-radius: 8px;
  cursor: pointer;
  border: 0.5px solid #E2E8F0;
  image-rendering: pixelated;
  transition: transform 0.2s;
}
#pixel-canvas:hover { transform: scale(1.02); }
.pixel-canvas-label { font-size: 11px; color: #94A3B8; }
.pixel-info-side {
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-width: 140px;
}
.pixel-info-item {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 8px;
  padding: 10px 14px;
}
.pixel-info-label { font-size: 10px; color: #94A3B8; text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 4px; }
.pixel-info-val { font-size: 15px; font-weight: 500; color: #6366F1; font-family: 'DM Mono', monospace; }

/* Resolution compare */
.resolution-compare {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  align-items: flex-end;
}
.res-compare-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}
.res-compare-grid {
  display: grid;
  gap: 1px;
  background: #E2E8F0;
  border: 0.5px solid #E2E8F0;
  border-radius: 4px;
  overflow: hidden;
}
.res-compare-pixel {
  background: #6366F1;
  opacity: 0.7;
}
.res-compare-label {
  font-size: 11px;
  color: #64748B;
  text-align: center;
  font-family: 'DM Mono', monospace;
}
.res-compare-title {
  font-size: 12px;
  font-weight: 500;
  color: #0F172A;
}

/* Colour depth visual */
.colour-depth-visual {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.colour-depth-row {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 12px 16px;
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 8px;
}
.colour-depth-bits {
  font-size: 14px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  color: #6366F1;
  min-width: 60px;
}
.colour-depth-swatches {
  display: flex;
  gap: 3px;
  flex-wrap: wrap;
  flex: 1;
}
.colour-swatch {
  width: 20px;
  height: 20px;
  border-radius: 3px;
  border: 0.5px solid rgba(0,0,0,0.1);
}
.colour-depth-info {
  font-size: 12px;
  color: #64748B;
  min-width: 120px;
  text-align: right;
}


/* ---- LESSON 12 — COMPRESSION ---- */

/* Suitcase analogy */
.suitcase-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.suitcase-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
.suitcase-card {
  border-radius: 12px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.lossy-card    { background: #FFF7ED; border: 0.5px solid #FED7AA; }
.lossless-card { background: #F0FDF4; border: 0.5px solid #86EFAC; }
.suitcase-icon { font-size: 28px; }
.suitcase-title {
  font-size: 14px;
  font-weight: 500;
  color: #0F172A;
}
.suitcase-analogy {
  font-size: 13px;
  color: #64748B;
  line-height: 1.7;
}
.suitcase-tag {
  font-size: 11px;
  font-weight: 500;
  padding: 4px 10px;
  border-radius: 20px;
  align-self: flex-start;
}
.lossy-tag    { background: #FEE2E2; color: #991B1B; }
.lossless-tag { background: #DCFCE7; color: #166534; }

/* Compression type sections */
.compression-type-wrap {
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.lossy-wrap    { background: #FFF7ED; border: 0.5px solid #FED7AA; }
.lossless-wrap { background: #F0FDF4; border: 0.5px solid #86EFAC; }
.compression-type-header {
  display: flex;
  align-items: center;
  gap: 10px;
}
.compression-badge {
  font-size: 11px;
  font-weight: 500;
  padding: 3px 10px;
  border-radius: 20px;
}
.lossy-badge    { background: #FEE2E2; color: #991B1B; }
.lossless-badge { background: #DCFCE7; color: #166534; }
.compression-type-title {
  font-size: 15px;
  font-weight: 500;
  color: #0F172A;
}
.lossy-examples {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 8px;
}
.compression-example-card {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 8px;
  padding: 12px;
  text-align: center;
}
.comp-ex-format {
  font-size: 16px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  color: #6366F1;
  margin-bottom: 4px;
}
.comp-ex-type {
  font-size: 11px;
  font-weight: 500;
  color: #0F172A;
  margin-bottom: 6px;
}
.comp-ex-note { font-size: 11px; color: #94A3B8; line-height: 1.5; }

/* Quality slider */
.quality-slider-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 10px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
#quality-canvas {
  width: 100%;
  height: 120px;
  border-radius: 6px;
  border: 0.5px solid #E2E8F0;
}
.quality-slider-row {
  display: flex;
  align-items: center;
  gap: 10px;
}
.quality-slider {
  flex: 1;
  accent-color: #6366F1;
  cursor: pointer;
}
.quality-label { font-size: 11px; color: #94A3B8; white-space: nowrap; }
.quality-info  { font-size: 12px; color: #64748B; font-family: 'DM Mono', monospace; }

/* RLE */
.rle-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 12px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.rle-title {
  font-size: 14px;
  font-weight: 500;
  color: #0F172A;
}
.rle-demo-wrap {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 8px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.rle-original, .rle-compressed {
  display: flex;
  gap: 2px;
  flex-wrap: wrap;
  align-items: center;
}
.rle-pixel {
  width: 28px;
  height: 28px;
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  font-weight: 500;
  color: #fff;
  font-family: 'DM Mono', monospace;
  transition: all 0.2s ease;
}
.rle-group {
  display: flex;
  align-items: center;
  gap: 4px;
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 6px;
  padding: 4px 8px;
  font-family: 'DM Mono', monospace;
  font-size: 13px;
  font-weight: 500;
  animation: popIn 0.3s ease;
}
.rle-group-count { color: #0F172A; }
.rle-group-val   { color: #6366F1; }
.rle-arrow-row { display: flex; gap: 10px; }
.rle-saving {
  font-size: 13px;
  font-weight: 500;
  color: #166534;
  background: #DCFCE7;
  padding: 8px 12px;
  border-radius: 6px;
}

/* RLE encoder */
.rle-encoder-wrap {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 8px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.rle-input-sequence {
  display: flex;
  gap: 2px;
  flex-wrap: wrap;
}
.rle-encode-hint { font-size: 12px; color: #94A3B8; line-height: 1.6; }

@media (max-width: 600px) {
  .suitcase-grid { grid-template-columns: 1fr; }
}


/* ---- WORKSHEET ---- */
.worksheet-progress-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 12px;
  padding: 16px 20px;
  display: flex;
  align-items: center;
  gap: 16px;
}
.worksheet-progress-label {
  font-size: 14px;
  font-weight: 500;
  color: #0F172A;
  white-space: nowrap;
  font-family: 'DM Mono', monospace;
}
.worksheet-progress-bar {
  flex: 1;
  height: 6px;
  background: #E2E8F0;
  border-radius: 3px;
  overflow: hidden;
}
.worksheet-progress-fill {
  height: 100%;
  background: #6366F1;
  border-radius: 3px;
  transition: width 0.5s ease;
}
.ws-question {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 12px;
  padding: 20px;
  display: flex;
  gap: 16px;
  transition: border-color 0.3s;
}
.ws-question.answered-correct {
  border-color: #22C55E;
  background: #F0FDF4;
}
.ws-question.answered-incorrect {
  border-color: #EF4444;
}
.ws-q-number {
  font-size: 12px;
  font-weight: 500;
  color: #6366F1;
  font-family: 'DM Mono', monospace;
  min-width: 28px;
  padding-top: 2px;
}
.ws-q-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.ws-q-text {
  font-size: 15px;
  color: #0F172A;
  line-height: 1.6;
  font-weight: 500;
}
.ws-mcq {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.ws-mcq .kb-option {
  text-align: left;
  padding: 12px 16px;
  width: 100%;
  white-space: normal;
  line-height: 1.5;
  font-size: 13px;
}
.ws-complete-wrap {
  background: #F0FDF4;
  border: 0.5px solid #86EFAC;
  border-radius: 16px;
  padding: 40px 32px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}
/* ---- CHAPTER COMPLETE BRANCHING SCREEN ---- */
.chapter-complete-paths {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 28px;
  width: 100%;
}
.chapter-path-card {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.chapter-path-next {
  border-color: #6366F1;
  background: #EEF2FF;
}
.chapter-path-test {
  background: #F8FAFC;
}
.locked-card {
  opacity: 0.75;
}
.chapter-path-tag {
  font-size: 10px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #6366F1;
  background: #E0E7FF;
  padding: 3px 10px;
  border-radius: 20px;
  align-self: flex-start;
}
.tag-addon {
  color: #92400E;
  background: #FEF3C7;
}
.chapter-path-icon {
  font-size: 28px;
  margin-top: 4px;
}
.chapter-path-title {
  font-size: 18px;
  font-weight: 500;
  color: #0F172A;
}
.chapter-path-subtitle {
  font-size: 13px;
  font-weight: 500;
  color: #6366F1;
}
.locked-card .chapter-path-subtitle {
  color: #94A3B8;
}
.chapter-path-desc {
  font-size: 13px;
  color: #64748B;
  line-height: 1.6;
  flex: 1;
}
.btn-chapter-next {
  background: #6366F1;
  color: #fff;
  border: none;
  padding: 12px 20px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
  transition: background 0.2s;
  margin-top: 8px;
  text-align: center;
}
.btn-chapter-next:hover { background: #4F46E5; }
.btn-chapter-test {
  background: #F1F5F9;
  color: #94A3B8;
  border: 0.5px solid #E2E8F0;
  padding: 12px 20px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 500;
  cursor: not-allowed;
  font-family: 'DM Sans', sans-serif;
  margin-top: 8px;
  text-align: center;
}
@media (max-width: 600px) {
  .chapter-complete-paths {
    grid-template-columns: 1fr;
  }
}


/* ============================================
   TOPIC 2 — DATA TRANSMISSION
   New components only. All shared styles
   (lesson-inner, tryit, nav, etc.) already
   in topic.css above.
============================================ */

/* ---- LESSON 1: TRANSMISSION ANALOGY ---- */
.transmission-analogy-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.analogy-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
.analogy-card {
  border-radius: 12px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.serial-card   { background: #EEF2FF; border: 0.5px solid #6366F1; }
.parallel-card { background: #FFF7ED; border: 0.5px solid #F59E0B; }
.analogy-icon  { font-size: 28px; }
.analogy-title { font-size: 14px; font-weight: 500; color: #0F172A; }
.analogy-desc  { font-size: 13px; color: #64748B; line-height: 1.6; }

/* Transmission demo */
.transmission-demo-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.transmission-controls { display: flex; gap: 10px; flex-wrap: wrap; }
.transmission-visual {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px;
  background: #F8FAFC;
  border-radius: 10px;
  border: 0.5px solid #E2E8F0;
  min-height: 80px;
}
.transmission-sender, .transmission-receiver {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  flex-shrink: 0;
}
.t-label  { font-size: 11px; color: #94A3B8; }
.t-device { font-size: 28px; }
.transmission-wires { flex: 1; display: flex; flex-direction: column; gap: 6px; }
.t-wire-wrap { display: flex; flex-direction: column; gap: 4px; }
.serial-wrap .t-wire { height: 28px; }
.t-wire-row { display: flex; align-items: center; gap: 8px; }
.t-wire-label { font-size: 10px; color: #94A3B8; width: 36px; font-family: 'DM Mono', monospace; flex-shrink: 0; }
.t-wire {
  flex: 1;
  height: 28px;
  background: #E2E8F0;
  border-radius: 4px;
  position: relative;
  overflow: visible;
}
.t-bit-travel {
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 24px;
  height: 24px;
  border-radius: 4px;
  background: #94A3B8;
  color: #fff;
  font-family: 'DM Mono', monospace;
  font-size: 12px;
  font-weight: 500;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: left 0.3s ease;
}
.t-bit-travel.is-one { background: #6366F1; }
.transmission-info { font-size: 13px; color: #64748B; min-height: 20px; }

/* ---- LESSON 2: DUPLEX ---- */
.duplex-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.duplex-selector { display: flex; gap: 8px; flex-wrap: wrap; }
.duplex-btn {
  background: #F1F5F9;
  border: 0.5px solid #E2E8F0;
  color: #64748B;
  padding: 9px 18px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
  transition: all 0.2s;
}
.duplex-btn:hover { border-color: #6366F1; color: #6366F1; }
.duplex-btn.active { background: #6366F1; border-color: #6366F1; color: #fff; }
.duplex-diagram {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 20px;
  background: #F8FAFC;
  border-radius: 10px;
}
.duplex-device { display: flex; flex-direction: column; align-items: center; gap: 4px; font-size: 28px; flex-shrink: 0; }
.duplex-device-label { font-size: 11px; color: #94A3B8; }
.duplex-arrows { flex: 1; display: flex; flex-direction: column; align-items: center; gap: 4px; }
.duplex-arrow { font-size: 16px; font-family: 'DM Mono', monospace; font-weight: 500; }
.duplex-mode-label { font-size: 11px; font-weight: 500; margin-top: 4px; }
.duplex-example { padding: 12px 0 4px; }
.duplex-example-text { font-size: 13px; color: #64748B; line-height: 1.6; }
.duplex-mcq { display: flex; flex-direction: column; gap: 8px; width: 100%; }
.duplex-mcq .kb-option { text-align: left; padding: 12px 16px; width: 100%; white-space: normal; line-height: 1.5; }

/* ---- LESSON 3: PACKETS ---- */
.packet-analogy-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.postal-steps { display: flex; flex-direction: column; gap: 12px; }
.postal-step {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  padding: 14px;
  background: #F8FAFC;
  border-radius: 8px;
  border: 0.5px solid #E2E8F0;
}
.postal-step-num {
  width: 32px;
  height: 32px;
  background: #6366F1;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 500;
  color: #fff;
  flex-shrink: 0;
}
.postal-step-title { font-size: 13px; font-weight: 500; color: #0F172A; margin-bottom: 4px; }
.postal-step-desc  { font-size: 13px; color: #64748B; line-height: 1.6; }

.packet-structure-wrap {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.packet-display { display: flex; gap: 0; border-radius: 8px; overflow: hidden; border: 0.5px solid #E2E8F0; }
.packet-part {
  flex: 1;
  padding: 16px 12px;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
}
.packet-header  { background: #EEF2FF; border-right: 0.5px solid #E2E8F0; }
.packet-payload { background: #F0FDF4; border-right: 0.5px solid #E2E8F0; }
.packet-trailer { background: #FEF3C7; }
.packet-part:hover { filter: brightness(0.95); }
.packet-part.selected { outline: 2px solid #6366F1; outline-offset: -2px; }
.packet-part-label { font-size: 13px; font-weight: 500; color: #0F172A; }
.packet-detail {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 8px;
  padding: 16px;
  min-height: 60px;
}
.packet-detail-placeholder { font-size: 13px; color: #CBD5E1; text-align: center; padding: 12px 0; }
.packet-detail-title { font-size: 14px; font-weight: 500; margin-bottom: 10px; }
.packet-detail-list { margin: 0; padding-left: 18px; display: flex; flex-direction: column; gap: 6px; }
.packet-detail-list li { font-size: 13px; color: #475569; line-height: 1.5; }

/* ---- LESSON 4: PROTOCOLS ---- */
.protocol-grid-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.protocol-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}
.protocol-card {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 8px;
  padding: 14px;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
}
.protocol-card:hover { border-color: #6366F1; background: #EEF2FF; }
.protocol-card.selected { border-color: #6366F1; background: #EEF2FF; }
.protocol-card-name { font-size: 16px; font-weight: 500; color: #6366F1; font-family: 'DM Mono', monospace; }
.protocol-detail {
  padding: 14px 16px;
  background: #EEF2FF;
  border-radius: 8px;
  border: 0.5px solid #6366F1;
  margin-top: 8px;
  animation: fadeIn 0.2s ease;
}
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
.protocol-detail-name { font-size: 16px; font-weight: 500; color: #6366F1; font-family: 'DM Mono', monospace; margin-bottom: 2px; }
.protocol-detail-full { font-size: 11px; color: #94A3B8; margin-bottom: 8px; }
.protocol-detail-desc { font-size: 13px; color: #475569; line-height: 1.6; }

.tcpip-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.tcpip-stack { display: flex; flex-direction: column; gap: 6px; }
.tcpip-layer {
  padding: 12px 16px;
  background: #F8FAFC;
  border-radius: 6px;
  border: 0.5px solid #E2E8F0;
}
.tcpip-layer-name      { font-size: 13px; font-weight: 500; margin-bottom: 2px; }
.tcpip-layer-protocols { font-size: 11px; font-family: 'DM Mono', monospace; color: #94A3B8; margin-bottom: 4px; }
.tcpip-layer-desc      { font-size: 12px; color: #64748B; }

/* ---- LESSON 5: PARITY ---- */
.parity-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.parity-selector { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.parity-mode-label { font-size: 12px; color: #64748B; }
.parity-mode-btn {
  background: #F1F5F9;
  border: 0.5px solid #E2E8F0;
  color: #64748B;
  padding: 7px 14px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 500;
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
  transition: all 0.2s;
}
.parity-mode-btn.active { background: #6366F1; border-color: #6366F1; color: #fff; }
.parity-register-wrap { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.parity-register { display: flex; gap: 4px; }
.parity-data-bit {
  width: 40px; height: 40px;
  display: flex; align-items: center; justify-content: center;
  font-size: 17px; font-weight: 500;
  font-family: 'DM Mono', monospace;
  border-radius: 8px;
  border: 0.5px solid #E2E8F0;
  background: #F8FAFC;
  color: #475569;
  cursor: pointer;
  transition: all 0.2s;
}
.parity-data-bit.is-one { background: #EEF2FF; border-color: #6366F1; color: #4338CA; }
.parity-data-bit:hover  { transform: scale(1.08); }
.parity-separator { font-size: 24px; color: #CBD5E1; line-height: 1; }
.parity-separator-small { font-size: 18px; color: #CBD5E1; margin: 0 4px; }
.parity-bit-wrap { display: flex; flex-direction: column; align-items: center; gap: 4px; }
.parity-bit-label { font-size: 10px; color: #94A3B8; text-transform: uppercase; letter-spacing: 0.06em; }
.parity-bit-display {
  width: 48px; height: 48px;
  display: flex; align-items: center; justify-content: center;
  font-size: 20px; font-weight: 500;
  font-family: 'DM Mono', monospace;
  border-radius: 10px;
  background: #F0FDF4; border: 1.5px solid #22C55E; color: #166534;
  transition: all 0.2s;
}
.parity-bit-display.is-one { background: #FEE2E2; border-color: #EF4444; color: #991B1B; }
.parity-explanation { font-size: 13px; color: #64748B; line-height: 1.6; }

/* Error demo */
.error-demo-wrap { display: flex; flex-direction: column; gap: 12px; }
.error-demo-row { display: flex; flex-direction: column; gap: 6px; padding: 12px 14px; background: #F8FAFC; border-radius: 8px; border: 0.5px solid #E2E8F0; }
.error-demo-label { font-size: 11px; font-weight: 500; color: #94A3B8; text-transform: uppercase; letter-spacing: 0.06em; }
.error-demo-bits  { display: flex; align-items: center; gap: 3px; }
.error-demo-note  { font-size: 12px; color: #64748B; }
.error-demo-result { min-height: 20px; }
.corrupted-bit { background: #EF4444 !important; border-color: #EF4444 !important; color: #fff !important; animation: pulse 0.5s ease; }
@keyframes pulse { 0%,100%{ transform: scale(1); } 50%{ transform: scale(1.2); } }
.parity-bit-sent { background: #FEF3C7; border-color: #F59E0B; color: #92400E; }

/* ---- LESSON 6: CHECKSUM ---- */
.error-step { background: #FEE2E2 !important; border-color: #EF4444 !important; }
.highlight-step { background: #FEF3C7 !important; border-color: #F59E0B !important; }

/* ---- LESSON 7: ARQ ---- */
.arq-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.arq-diagram {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 20px;
  background: #F8FAFC;
  border-radius: 10px;
  border: 0.5px solid #E2E8F0;
  min-height: 100px;
}
.arq-device { display: flex; flex-direction: column; align-items: center; gap: 4px; flex-shrink: 0; }
.arq-device-label  { font-size: 11px; color: #94A3B8; }
.arq-device-status { font-size: 11px; color: #64748B; text-align: center; max-width: 90px; }
.arq-channel {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  min-height: 60px;
  position: relative;
}
.arq-packet-visual, .arq-ack-visual {
  padding: 6px 14px;
  border-radius: 6px;
  font-size: 13px;
  font-weight: 500;
  font-family: 'DM Sans', sans-serif;
}
.arq-packet-inner { background: #EEF2FF; color: #4338CA; padding: 6px 12px; border-radius: 6px; }
.arq-packet-inner.corrupted { background: #FEE2E2; color: #991B1B; }
.arq-ack-inner { background: #DCFCE7; color: #166534; padding: 6px 12px; border-radius: 6px; font-family: 'DM Mono', monospace; }
.arq-ack-inner.nak { background: #FEE2E2; color: #991B1B; }
.arq-controls { display: flex; gap: 10px; flex-wrap: wrap; }
.arq-log { max-height: 120px; overflow-y: auto; display: flex; flex-direction: column; gap: 4px; }

/* ---- LESSON 8: ENCRYPTION ---- */
.encryption-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.caesar-interactive { display: flex; flex-direction: column; gap: 14px; }
.caesar-input-row { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; }
.caesar-shift-wrap { display: flex; align-items: center; gap: 8px; }
.caesar-result { display: flex; flex-direction: column; gap: 10px; }
.caesar-row { display: flex; align-items: center; gap: 12px; }
.caesar-row-label { font-size: 11px; color: #94A3B8; width: 70px; flex-shrink: 0; text-transform: uppercase; letter-spacing: 0.05em; }
.caesar-chars { display: flex; gap: 4px; flex-wrap: wrap; }
.caesar-char {
  width: 32px; height: 36px;
  display: flex; align-items: center; justify-content: center;
  font-size: 16px; font-weight: 500;
  font-family: 'DM Mono', monospace;
  border-radius: 6px;
  border: 0.5px solid #E2E8F0;
}
.caesar-char.plain     { background: #F8FAFC; color: #0F172A; }
.caesar-char.encrypted { background: #EEF2FF; color: #6366F1; border-color: #6366F1; }
.caesar-note { font-size: 12px; color: #94A3B8; }
.padlock-wrap {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

/* ---- LESSON 9: SECURITY ---- */
.security-concepts-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.security-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}
.security-card {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 10px;
  padding: 16px;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
}
.security-card:hover  { border-color: #6366F1; background: #EEF2FF; }
.security-card.selected { border-color: #6366F1; background: #EEF2FF; }
.security-card-icon { font-size: 28px; margin-bottom: 6px; }
.security-card-name { font-size: 13px; font-weight: 500; color: #0F172A; }
.security-detail {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 10px;
  padding: 16px;
  min-height: 60px;
  animation: fadeIn 0.2s ease;
}
.handshake-steps { display: flex; flex-direction: column; gap: 8px; }

/* Beyond syllabus box */
.beyond-syllabus-wrap {
  background: #0F172A;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.beyond-syllabus-tag {
  font-size: 10px;
  font-weight: 500;
  color: #F59E0B;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.beyond-syllabus-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.beyond-card { background: rgba(255,255,255,0.05); border-radius: 10px; padding: 16px; }
.beyond-title { font-size: 13px; font-weight: 500; color: #F8FAFC; margin-bottom: 6px; }
.beyond-desc  { font-size: 12px; color: #94A3B8; line-height: 1.6; }

@media (max-width: 600px) {
  .analogy-grid          { grid-template-columns: 1fr; }
  .protocol-grid         { grid-template-columns: repeat(2, 1fr); }
  .security-grid         { grid-template-columns: 1fr; }
  .beyond-syllabus-grid  { grid-template-columns: 1fr; }
}


/* ============================================
   TOPIC 2 — VISUAL UPGRADES
   Envelope builder, protocol journey,
   HTTP/HTTPS comparison, firewall demo,
   proxy demo
============================================ */

/* ---- ENVELOPE / PACKET BUILDER ---- */
.envelope-outer {
  display: flex;
  flex-direction: column;
  gap: 0;
  border-radius: 14px;
  overflow: hidden;
  border: 1.5px solid #E2E8F0;
  background: #fff;
}
.envelope-header-zone {
  background: #EEF2FF;
  border-bottom: 1.5px solid #6366F1;
  padding: 16px;
}
.envelope-payload-zone {
  background: #F0FDF4;
  border-bottom: 1.5px solid #86EFAC;
  padding: 14px 16px;
  min-height: 52px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.envelope-trailer-zone {
  background: #FEF3C7;
  padding: 14px 16px;
  min-height: 48px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.envelope-zone-label {
  font-size: 10px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 8px;
}
.envelope-fields {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.envelope-field {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 10px;
  border-radius: 6px;
  border: 1px dashed #CBD5E1;
  background: #fff;
  transition: all 0.3s ease;
  min-width: 120px;
}
.envelope-field.empty .envelope-field-name { color: #CBD5E1; }
.envelope-field.empty .envelope-field-letter { color: #CBD5E1; }
.envelope-field.filled {
  border: 1px solid #6366F1;
  background: #EEF2FF;
  animation: fieldPop 0.3s ease;
}
@keyframes fieldPop { 0%{ transform:scale(0.9); } 60%{ transform:scale(1.05); } 100%{ transform:scale(1); } }
.envelope-field.filled .envelope-field-letter { color: #6366F1; }
.envelope-field.filled .envelope-field-name   { color: #0F172A; }
.envelope-field-letter {
  font-size: 18px;
  font-weight: 500;
  font-family: 'DM Mono', monospace;
  width: 20px;
  text-align: center;
}
.envelope-field-name { font-size: 12px; font-weight: 500; }
.envelope-payload-content, .envelope-trailer-content {
  font-size: 13px;
  color: #475569;
  font-weight: 500;
  transition: all 0.3s ease;
}
.envelope-payload-content.hidden, .envelope-trailer-content.hidden { opacity: 0; }
.envelope-desc {
  margin-top: 12px;
  font-size: 13px;
  color: #475569;
  line-height: 1.6;
  padding: 10px 12px;
  background: #F8FAFC;
  border-radius: 8px;
  border: 0.5px solid #E2E8F0;
  min-height: 40px;
  transition: all 0.3s ease;
}

/* ---- PROTOCOL JOURNEY ---- */
.protocol-journey-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.journey-track {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  overflow-x: auto;
  padding: 8px 0;
}
.journey-stop {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  padding: 12px 8px;
  border-radius: 10px;
  border: 1.5px solid #E2E8F0;
  background: #F8FAFC;
  transition: all 0.2s;
  min-width: 110px;
  flex-shrink: 0;
}
.journey-stop:hover { border-color: #6366F1; background: #EEF2FF; }
.journey-stop.active { border-color: #6366F1; background: #EEF2FF; box-shadow: 0 0 0 3px #EEF2FF; }
.journey-stop-icon {
  font-size: 28px;
  width: 52px; height: 52px;
  border-radius: 50%;
  border: 2px solid #E2E8F0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #fff;
  transition: border-color 0.2s;
}
.journey-stop.active .journey-stop-icon { border-color: inherit; }
.journey-stop-label { font-size: 12px; font-weight: 500; color: #0F172A; text-align: center; }
.journey-stop-protocols { display: flex; flex-wrap: wrap; gap: 4px; justify-content: center; }
.journey-protocol-tag {
  font-size: 10px;
  font-weight: 500;
  padding: 2px 6px;
  border-radius: 10px;
  font-family: 'DM Mono', monospace;
}
.journey-arrow {
  font-size: 20px;
  color: #CBD5E1;
  padding-top: 28px;
  flex-shrink: 0;
}
.journey-detail {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 10px;
  padding: 16px;
  min-height: 80px;
  animation: fadeIn 0.2s ease;
}
.journey-detail-title { font-size: 14px; font-weight: 500; margin-bottom: 8px; }
.journey-detail-body  { font-size: 13px; color: #475569; line-height: 1.6; margin-bottom: 12px; }
.journey-detail-protocols { display: flex; flex-direction: column; gap: 8px; }
.journey-proto-item {
  padding: 8px 12px;
  background: #fff;
  border-radius: 6px;
  border: 0.5px solid #E2E8F0;
}
.journey-proto-name { font-size: 12px; font-weight: 500; font-family: 'DM Mono', monospace; color: #6366F1; margin-bottom: 2px; }
.journey-proto-desc { font-size: 12px; color: #64748B; line-height: 1.5; }

/* ---- HTTP vs HTTPS ---- */
.https-comparison-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.https-toggle { display: flex; gap: 8px; }
.https-journey {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px;
  background: #F8FAFC;
  border-radius: 10px;
}
.https-node { font-size: 13px; font-weight: 500; color: #0F172A; text-align: center; flex-shrink: 0; }
.https-wire {
  flex: 1;
  height: 40px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-family: 'DM Mono', monospace;
  padding: 0 12px;
}
.http-wire  { background: #FEE2E2; border: 1px dashed #EF4444; }
.https-wire-secure { background: #DCFCE7; border: 1px solid #22C55E; }
.https-data-exposed   { color: #991B1B; font-size: 12px; }
.https-data-encrypted { color: #166534; font-size: 12px; }

/* ---- FIREWALL DEMO ---- */
.fw-demo-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.fw-diagram {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 16px;
  background: #F8FAFC;
  border-radius: 10px;
  border: 0.5px solid #E2E8F0;
}
.fw-node {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  font-size: 24px;
  flex-shrink: 0;
}
.fw-node-label { font-size: 10px; color: #94A3B8; }
.fw-channel {
  flex: 1;
  height: 36px;
  background: #E2E8F0;
  border-radius: 4px;
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
}
.fw-packet-vis {
  position: absolute;
  left: 0;
  font-size: 12px;
  font-weight: 500;
  padding: 4px 8px;
  background: #EEF2FF;
  border-radius: 4px;
  white-space: nowrap;
  color: #4338CA;
}
.fw-packet-moving {
  animation: fwSlide 0.7s ease forwards;
}
.fw-packet-out-moving {
  animation: fwSlideOut 0.5s ease forwards;
}
@keyframes fwSlide    { from{ left:0; } to{ left:100%; } }
@keyframes fwSlideOut { from{ left:0; opacity:1; } to{ left:100%; opacity:0; } }
.fw-guard {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 10px 12px;
  background: #fff;
  border: 1.5px solid #E2E8F0;
  border-radius: 10px;
  flex-shrink: 0;
  transition: all 0.3s;
}
.fw-guard-icon  { font-size: 22px; }
.fw-guard-label { font-size: 10px; font-weight: 500; color: #64748B; }
.fw-rulebook    { font-size: 10px; color: #94A3B8; }
.fw-guard.fw-allow { border-color: #22C55E; background: #F0FDF4; }
.fw-guard.fw-block { border-color: #EF4444; background: #FEF2F2; animation: fwShake 0.3s ease; }
@keyframes fwShake { 0%,100%{ transform:translateX(0); } 25%{ transform:translateX(-4px); } 75%{ transform:translateX(4px); } }
.fw-log { max-height: 110px; overflow-y: auto; display: flex; flex-direction: column; gap: 3px; }

/* ---- PROXY DEMO ---- */
.proxy-diagram {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px;
  background: #F8FAFC;
  border-radius: 10px;
  border: 0.5px solid #E2E8F0;
  flex-wrap: wrap;
}
.proxy-node {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  font-size: 24px;
  flex-shrink: 0;
  text-align: center;
}
.proxy-node-label { font-size: 10px; color: #94A3B8; }
.proxy-arrow-wrap { flex: 1; height: 2px; background: #CBD5E1; min-width: 20px; position: relative; }
.proxy-server-node {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 10px 14px;
  background: #EEF2FF;
  border: 1.5px solid #6366F1;
  border-radius: 10px;
  flex-shrink: 0;
}
.proxy-server-icon  { font-size: 24px; }
.proxy-server-label { font-size: 10px; font-weight: 500; color: #6366F1; }
.proxy-cache-label  { font-size: 10px; color: #F59E0B; }
.proxy-student2-row {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  background: #F0FDF4;
  border-radius: 10px;
  border: 0.5px solid #86EFAC;
  flex-wrap: wrap;
}
.proxy-log { max-height: 100px; overflow-y: auto; display: flex; flex-direction: column; gap: 3px; }

@media (max-width: 600px) {
  .journey-track { flex-direction: column; align-items: stretch; }
  .journey-arrow { display: none; }
  .https-journey { flex-direction: column; }
  .fw-diagram { flex-wrap: wrap; }
}


/* ============================================
   TOPIC 3 — HARDWARE
   CPU explorer, FDE cycle, performance sliders,
   storage explorer, RAM/ROM demo, virtual memory,
   I/O device explorer
============================================ */

/* ---- LESSON 1: CPU EXPLORER ---- */
.cpu-explorer-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.cpu-diagram {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  padding: 16px;
  background: #0F172A;
  border-radius: 12px;
  position: relative;
}
.cpu-outer-label {
  grid-column: 1 / -1;
  font-size: 10px;
  font-weight: 500;
  color: #475569;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  text-align: center;
  margin-bottom: -6px;
}
.cpu-component {
  background: rgba(99,102,241,0.08);
  border: 1px solid rgba(99,102,241,0.2);
  border-radius: 10px;
  padding: 16px 12px;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
}
.cpu-component:hover { border-color: #6366F1; background: rgba(99,102,241,0.15); }
.cpu-component.active { border-color: #6366F1; background: rgba(99,102,241,0.2); box-shadow: 0 0 0 2px rgba(99,102,241,0.3); }
.cpu-comp-name { font-size: 16px; font-weight: 500; font-family: 'DM Mono', monospace; color: #fff; margin-bottom: 4px; }
.cpu-comp-full { font-size: 10px; color: #64748B; }
.cpu-detail-panel { background: #F8FAFC; border: 0.5px solid #E2E8F0; border-radius: 10px; padding: 16px; min-height: 60px; }

/* ---- LESSON 2: FDE CYCLE ---- */
.fde-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.fde-diagram {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 12px;
  align-items: start;
  background: #0F172A;
  border-radius: 12px;
  padding: 16px;
}
.fde-ram {
  background: rgba(255,255,255,0.04);
  border: 0.5px solid rgba(255,255,255,0.1);
  border-radius: 10px;
  padding: 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.fde-ram-label { font-size: 10px; color: #64748B; text-transform: uppercase; letter-spacing: 0.06em; margin-bottom: 6px; }
.fde-ram-row { display: flex; align-items: center; gap: 6px; padding: 4px 6px; border-radius: 4px; transition: background 0.3s; }
.fde-addr { font-size: 11px; font-family: 'DM Mono', monospace; color: #475569; width: 28px; flex-shrink: 0; }
.fde-val  { font-size: 11px; font-family: 'DM Mono', monospace; color: #94A3B8; }

.fde-bus-area {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 8px 4px;
  align-self: center;
}
.fde-bus-label { font-size: 9px; color: #475569; text-transform: uppercase; letter-spacing: 0.06em; text-align: center; }
.fde-address-bus, .fde-data-bus { display: flex; flex-direction: column; gap: 3px; }
.fde-bus-name { font-size: 9px; color: #475569; text-align: center; }
.fde-bus-line {
  width: 60px;
  height: 12px;
  background: rgba(255,255,255,0.06);
  border-radius: 3px;
  position: relative;
  overflow: hidden;
  border: 0.5px solid rgba(255,255,255,0.08);
  transition: background 0.3s, border-color 0.3s;
}
.fde-signal {
  position: absolute;
  left: 0;
  top: 0;
  height: 100%;
  width: 16px;
  background: #6366F1;
  border-radius: 2px;
  opacity: 0;
}

.fde-cpu {
  background: rgba(99,102,241,0.06);
  border: 0.5px solid rgba(99,102,241,0.2);
  border-radius: 10px;
  padding: 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.fde-cpu-label { font-size: 10px; color: #6366F1; text-transform: uppercase; letter-spacing: 0.06em; }
.fde-registers { display: flex; flex-direction: column; gap: 4px; }
.fde-register {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 5px 8px;
  background: rgba(255,255,255,0.04);
  border: 0.5px solid rgba(255,255,255,0.08);
  border-radius: 6px;
  transition: background 0.3s, border-color 0.3s;
}
.fde-reg-name  { font-size: 10px; font-weight: 500; font-family: 'DM Mono', monospace; color: #6366F1; width: 28px; flex-shrink: 0; }
.fde-reg-value { font-size: 12px; font-family: 'DM Mono', monospace; color: #fff; flex: 1; transition: all 0.3s; }
.fde-reg-full  { font-size: 9px; color: #475569; }
.fde-alu {
  padding: 8px;
  background: rgba(245,158,11,0.08);
  border: 0.5px solid rgba(245,158,11,0.2);
  border-radius: 6px;
  text-align: center;
  transition: border-color 0.3s, box-shadow 0.3s;
}
.fde-alu-label { font-size: 10px; color: #F59E0B; font-weight: 500; }

.fde-controls { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.fde-stage-badge {
  font-size: 11px;
  font-weight: 500;
  color: #fff;
  background: #475569;
  padding: 4px 12px;
  border-radius: 20px;
  font-family: 'DM Mono', monospace;
  transition: background 0.3s;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.fde-controls-row { display: flex; gap: 8px; }
.fde-explanation { font-size: 13px; color: #475569; line-height: 1.7; padding: 12px 14px; background: #F8FAFC; border-radius: 8px; border: 0.5px solid #E2E8F0; min-height: 48px; transition: all 0.3s; }
.fde-log { max-height: 120px; overflow-y: auto; display: flex; flex-direction: column; gap: 3px; }

/* ---- LESSON 3: CPU PERFORMANCE ---- */
.cpu-perf-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.cpu-perf-grid { display: flex; flex-direction: column; gap: 12px; }
.cpu-perf-card {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 10px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.cpc-title { font-size: 13px; font-weight: 500; color: #0F172A; }
.cpc-value { font-size: 22px; font-weight: 500; font-family: 'DM Mono', monospace; color: #6366F1; }
.cpc-slider { width: 100%; height: 4px; cursor: pointer; accent-color: #6366F1; }
.cpc-labels { display: flex; justify-content: space-between; font-size: 11px; color: #94A3B8; }
.cpc-desc { font-size: 12px; color: #64748B; line-height: 1.5; }

.cpu-perf-result { padding: 14px; background: #EEF2FF; border-radius: 10px; border: 0.5px solid #C7D2FE; }
.cpu-perf-bar-wrap { display: flex; flex-direction: column; gap: 6px; margin-bottom: 10px; }
.cpu-perf-bar-label { font-size: 12px; color: #6366F1; font-weight: 500; }
.cpu-perf-bar-track { height: 10px; background: #E0E7FF; border-radius: 5px; overflow: hidden; }
.cpu-perf-bar-fill { height: 100%; background: linear-gradient(to right, #6366F1, #8B5CF6); border-radius: 5px; transition: width 0.4s ease; }
.cpu-perf-pct { font-size: 20px; font-weight: 500; font-family: 'DM Mono', monospace; color: #6366F1; }
.cpu-perf-breakdown { display: flex; flex-direction: column; gap: 3px; }
.cpu-perf-breakdown span { font-size: 12px; color: #64748B; }

/* ---- LESSON 4: STORAGE EXPLORER ---- */
.storage-explorer-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.storage-selector { display: flex; gap: 8px; flex-wrap: wrap; }
.storage-btn {
  background: #F1F5F9;
  border: 0.5px solid #E2E8F0;
  color: #64748B;
  padding: 9px 20px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
  transition: all 0.2s;
}
.storage-btn:hover { border-color: #6366F1; color: #6366F1; }
.storage-btn.active { background: #6366F1; border-color: #6366F1; color: #fff; }
.storage-detail { background: #F8FAFC; border: 0.5px solid #E2E8F0; border-radius: 10px; padding: 18px; min-height: 80px; }
.storage-detail-header { display: flex; align-items: center; gap: 10px; margin-bottom: 12px; }
.storage-detail-icon { font-size: 24px; }
.storage-detail-title { font-size: 15px; font-weight: 500; }
.storage-detail-how { font-size: 13px; color: #475569; line-height: 1.7; margin-bottom: 14px; }
.storage-pros-cons { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.spc-label { font-size: 11px; font-weight: 500; text-transform: uppercase; letter-spacing: 0.06em; margin-bottom: 6px; }
.spc-list { padding-left: 16px; display: flex; flex-direction: column; gap: 4px; }
.spc-list li { font-size: 12px; color: #64748B; line-height: 1.5; }

/* ---- LESSON 5: RAM vs ROM ---- */
.memory-compare-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.memory-power-row { display: flex; align-items: center; gap: 14px; }
.memory-power-label { font-size: 13px; font-weight: 500; color: #475569; }
.power-switch-wrap { display: flex; align-items: center; gap: 10px; cursor: pointer; }
.power-switch {
  width: 52px;
  height: 28px;
  background: #22C55E;
  border-radius: 14px;
  display: flex;
  align-items: center;
  padding: 3px;
  transition: background 0.3s;
}
.power-switch.off { background: #CBD5E1; }
.power-switch .power-switch-knob {
  width: 22px;
  height: 22px;
  background: #fff;
  border-radius: 50%;
  transition: transform 0.3s;
  box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}
.power-switch.off .power-switch-knob { transform: none; }
.power-switch:not(.off) .power-switch-knob { transform: translateX(24px); }
.power-switch-label { font-size: 13px; font-weight: 500; color: #0F172A; width: 28px; }

.memory-cards-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.memory-card {
  border: 0.5px solid #E2E8F0;
  border-radius: 12px;
  padding: 16px;
  background: #F8FAFC;
  transition: all 0.3s;
}
.memory-card.powered-off { opacity: 0.7; }
.mem-card-header { margin-bottom: 12px; }
.mem-card-title { font-size: 18px; font-weight: 500; color: #0F172A; font-family: 'DM Mono', monospace; }
.mem-card-sub { font-size: 11px; color: #94A3B8; }
.mem-card-visual { display: flex; flex-direction: column; gap: 4px; margin-bottom: 12px; }
.mem-cell {
  font-size: 12px;
  padding: 6px 10px;
  border-radius: 5px;
  background: #E2E8F0;
  color: #94A3B8;
  font-family: 'DM Mono', monospace;
  transition: all 0.4s;
}
.mem-cell.active { background: #EEF2FF; color: #4338CA; border: 0.5px solid #C7D2FE; }
.mem-cell.rom-cell.active { background: #F0FDF4; color: #166534; border-color: #86EFAC; }
.mem-cell.lost { background: #FEE2E2; color: #DC2626; text-decoration: line-through; }
.mem-card-status { font-size: 12px; color: #64748B; margin-bottom: 12px; font-style: italic; }
.mem-card-props { display: flex; flex-direction: column; gap: 4px; }
.mem-prop { display: flex; gap: 8px; font-size: 12px; }
.mem-prop-k { color: #94A3B8; width: 70px; flex-shrink: 0; }
.mem-prop-v { color: #0F172A; font-weight: 500; }

/* ---- LESSON 6: VIRTUAL MEMORY ---- */
.vm-demo-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.vm-controls { display: flex; gap: 10px; flex-wrap: wrap; }
.vm-diagram { display: flex; flex-direction: column; gap: 10px; }
.vm-section { display: flex; flex-direction: column; gap: 6px; }
.vm-section-header { font-size: 11px; font-weight: 500; text-transform: uppercase; letter-spacing: 0.06em; padding: 4px 10px; border-radius: 6px; align-self: flex-start; }
.ram-header { background: #EEF2FF; color: #4338CA; }
.vm-header  { background: #FEF3C7; color: #92400E; }
.vm-slots   { display: flex; flex-wrap: wrap; gap: 6px; }
.vm-slot { padding: 6px 14px; border-radius: 6px; font-size: 13px; font-weight: 500; font-family: 'DM Sans', sans-serif; animation: slotPop 0.3s ease; }
@keyframes slotPop { from { transform: scale(0.85); opacity: 0; } to { transform: scale(1); opacity: 1; } }
.vm-slot.filled  { background: #EEF2FF; color: #4338CA; border: 0.5px solid #C7D2FE; }
.vm-slot.empty   { background: #F1F5F9; color: #CBD5E1; border: 0.5px dashed #E2E8F0; }
.vm-slot.virtual { background: #FEF3C7; color: #92400E; border: 0.5px solid #FCD34D; display: flex; align-items: center; gap: 6px; }
.vm-slow-tag { font-size: 10px; background: #F59E0B; color: #fff; padding: 1px 6px; border-radius: 4px; }
.vm-overflow-arrow { font-size: 12px; color: #EF4444; font-weight: 500; padding: 4px 0; }
.vm-explanation { font-size: 13px; color: #475569; line-height: 1.7; padding: 12px 14px; background: #F8FAFC; border-radius: 8px; border: 0.5px solid #E2E8F0; min-height: 40px; transition: color 0.3s; }

/* ---- LESSONS 7+8: I/O DEVICES ---- */
.io-explorer-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.io-device-grid { display: flex; flex-wrap: wrap; gap: 8px; }
.io-device-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 12px 10px;
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.2s;
  min-width: 80px;
}
.io-device-card:hover { border-color: #6366F1; background: #EEF2FF; }
.io-device-card.active { border-color: #6366F1; background: #EEF2FF; }
.io-device-icon { font-size: 24px; }
.io-device-name { font-size: 11px; font-weight: 500; color: #0F172A; text-align: center; }
.io-device-detail { background: #F8FAFC; border: 0.5px solid #E2E8F0; border-radius: 10px; padding: 18px; min-height: 60px; animation: fadeIn 0.2s ease; }
.io-detail-title { font-size: 16px; font-weight: 500; color: #0F172A; margin-bottom: 10px; }
.io-detail-how { font-size: 13px; color: #475569; line-height: 1.7; margin-bottom: 10px; }
.io-detail-converts { font-size: 13px; color: #475569; }
.io-converts-text { color: #6366F1; font-family: 'DM Mono', monospace; font-size: 12px; }

/* Desktop layout */
@media (min-width: 768px) {
  .cpu-perf-grid { flex-direction: row; }
  .cpu-perf-card { flex: 1; }
  .memory-cards-grid { grid-template-columns: 1fr 1fr; }
  .storage-pros-cons { grid-template-columns: 1fr 1fr; }
  .fde-diagram { grid-template-columns: 180px auto 1fr; }
}


/* ============================================
   TOPIC 2 PATCHES — Echo check + Check digit
============================================ */
.echo-demo-wrap {
  background: #F8FAFC;
  border: 0.5px solid #E2E8F0;
  border-radius: 12px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.echo-diagram {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px;
  background: #0F172A;
  border-radius: 10px;
  flex-wrap: wrap;
}
.echo-node {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  font-size: 22px;
  flex-shrink: 0;
}
.echo-node-label { font-size: 10px; color: #64748B; }
.echo-node-data  { font-size: 11px; font-family: 'DM Mono', monospace; color: #6366F1; }
.echo-channel {
  flex: 1;
  height: 12px;
  background: rgba(255,255,255,0.06);
  border-radius: 4px;
  position: relative;
  min-width: 30px;
}
.echo-arrow {
  position: absolute;
  left: 0; top: 0;
  height: 100%;
  width: 0;
  background: #6366F1;
  border-radius: 4px;
  transition: none;
}
.echo-arrow.arrow-active {
  animation: echoSlide 0.7s ease forwards;
}
.echo-arrow-back.arrow-active {
  animation: echoSlideBack 0.7s ease forwards;
}
@keyframes echoSlide     { from{ width:0; } to{ width:100%; } }
@keyframes echoSlideBack { from{ width:0; } to{ width:100%; } }
.echo-compare  { font-size: 13px; padding: 10px 12px; border-radius: 8px; border: 0.5px solid #E2E8F0; }
.echo-match    { color: #166534; }
.echo-mismatch { color: #991B1B; }
.echo-result   { font-size: 12px; color: #64748B; min-height: 16px; }

.check-digit-wrap { background: #F8FAFC; border: 0.5px solid #E2E8F0; border-radius: 12px; padding: 16px; }
.isbn-demo { display: flex; flex-direction: column; gap: 12px; }
.isbn-number { font-size: 14px; font-weight: 500; font-family: 'DM Mono', monospace; color: #0F172A; }
.isbn-label { margin-bottom: 8px; }
.isbn-check-digit { color: #6366F1; }
.isbn-digits { display: flex; gap: 4px; flex-wrap: wrap; }
.isbn-digit-cell {
  display: flex; flex-direction: column; align-items: center;
  padding: 6px 8px; background: #fff;
  border: 0.5px solid #E2E8F0; border-radius: 6px;
  transition: all 0.3s; min-width: 38px;
}
.isbn-digit-cell.highlighted { background: #EEF2FF; border-color: #6366F1; }
.isbn-check-cell { background: #F8FAFC; border-style: dashed; }
.isbn-check-cell.highlighted { background: #DCFCE7; border-color: #22C55E; border-style: solid; }
.isbn-digit-val { font-size: 16px; font-weight: 500; font-family: 'DM Mono', monospace; color: #0F172A; }
.isbn-digit-pos { font-size: 10px; color: #94A3B8; }
.isbn-steps { display: flex; flex-direction: column; gap: 6px; max-height: 200px; overflow-y: auto; }


/* ============================================
   TOPIC 4 — SOFTWARE
   Software stack, OS functions, interrupt demo,
   language levels, compiler/interpreter, IDE sim
============================================ */

/* ---- LESSON 1: SOFTWARE STACK ---- */
.sw-stack-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.sw-stack { display: flex; flex-direction: column; gap: 6px; }
.sw-layer {
  padding: 14px 18px;
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.2s;
  border: 1.5px solid transparent;
}
.sw-layer:hover { transform: translateX(4px); }
.sw-layer.selected { border-color: currentColor; transform: translateX(4px); }
.app-layer { background: #EEF2FF; color: #4338CA; }
.os-layer  { background: #FEF3C7; color: #92400E; }
.fw-layer  { background: #DCFCE7; color: #166534; }
.hw-layer  { background: #FEE2E2; color: #991B1B; }
.sw-layer-name     { font-size: 14px; font-weight: 500; }
.sw-layer-examples { font-size: 11px; opacity: 0.7; margin-top: 2px; }
.sw-layer-detail { background: #F8FAFC; border: 0.5px solid #E2E8F0; border-radius: 10px; padding: 16px; min-height: 60px; }
.utility-grid { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.utility-card {
  display: flex; flex-direction: column; align-items: center; gap: 6px;
  padding: 10px 12px; background: #F8FAFC;
  border: 0.5px solid #E2E8F0; border-radius: 10px;
  cursor: pointer; transition: all 0.2s; min-width: 90px;
}
.utility-card:hover { border-color: #6366F1; background: #EEF2FF; }
.utility-card.active { border-color: #6366F1; background: #EEF2FF; }
.utility-icon { font-size: 22px; }
.utility-name { font-size: 11px; font-weight: 500; color: #0F172A; text-align: center; }
.utility-detail { font-size: 13px; color: #475569; line-height: 1.7; padding: 10px 14px; background: #F8FAFC; border-radius: 8px; border: 0.5px solid #E2E8F0; margin-top: 8px; animation: fadeIn 0.2s ease; }

/* ---- LESSON 2: OS FUNCTIONS ---- */
.os-sim-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.os-functions-grid { display: flex; flex-wrap: wrap; gap: 8px; }
.os-func-card {
  display: flex; flex-direction: column; align-items: center; gap: 6px;
  padding: 12px 10px; background: #F8FAFC;
  border: 0.5px solid #E2E8F0; border-radius: 10px;
  cursor: pointer; transition: all 0.2s; min-width: 100px;
}
.os-func-card:hover { border-color: #6366F1; background: #EEF2FF; }
.os-func-card.active { border-color: #6366F1; background: #EEF2FF; }
.osf-icon { font-size: 22px; }
.osf-name { font-size: 11px; font-weight: 500; color: #0F172A; text-align: center; line-height: 1.4; }
.os-function-detail { background: #F8FAFC; border: 0.5px solid #E2E8F0; border-radius: 10px; padding: 16px; min-height: 60px; animation: fadeIn 0.2s ease; }

/* ---- LESSON 3: INTERRUPT DEMO ---- */
.interrupt-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.interrupt-diagram { display: flex; gap: 12px; flex-wrap: wrap; }
.interrupt-box {
  flex: 1;
  min-width: 160px;
  background: #0F172A;
  border: 1.5px solid rgba(255,255,255,0.1);
  border-radius: 10px;
  padding: 16px;
  transition: border-color 0.4s;
}
.int-box-label  { font-size: 10px; color: #64748B; text-transform: uppercase; letter-spacing: 0.07em; margin-bottom: 8px; }
.int-box-status { font-size: 13px; color: #94A3B8; font-family: 'DM Mono', monospace; line-height: 1.5; }

/* ---- LESSON 4: LANGUAGE LEVELS ---- */
.lang-levels-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.lang-levels-selector { display: flex; gap: 8px; flex-wrap: wrap; }
.lang-btn {
  background: #F1F5F9; border: 0.5px solid #E2E8F0;
  color: #64748B; padding: 9px 18px; border-radius: 8px;
  font-size: 13px; font-weight: 500; cursor: pointer;
  font-family: 'DM Sans', sans-serif; transition: all 0.2s;
}
.lang-btn:hover { border-color: #6366F1; color: #6366F1; }
.lang-btn.active { background: #6366F1; border-color: #6366F1; color: #fff; }
.lang-display { background: #0F172A; border-radius: 10px; padding: 18px; display: flex; flex-direction: column; gap: 10px; }
.lang-level-header { font-size: 12px; font-weight: 500; text-transform: uppercase; letter-spacing: 0.06em; }
.lang-code-block { display: flex; flex-direction: column; gap: 4px; border-left: 2px solid #334155; padding-left: 14px; }
.lang-code-line { font-size: 13px; font-family: 'DM Mono', monospace; color: #94A3B8; line-height: 1.6; }
.lang-level-note { font-size: 12px; color: #64748B; line-height: 1.6; }

/* ---- LESSON 5: COMPILER/INTERPRETER ---- */
.ci-demo-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.ci-code-panel { background: #0F172A; border-radius: 10px; overflow: hidden; }
.ci-code-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 10px 16px; background: rgba(255,255,255,0.04);
  border-bottom: 0.5px solid rgba(255,255,255,0.07);
}
.ci-code-title { font-size: 12px; font-family: 'DM Mono', monospace; color: #64748B; }
.ci-translator-selector { display: flex; gap: 6px; }
.ci-select-btn {
  background: rgba(255,255,255,0.06); border: 0.5px solid rgba(255,255,255,0.1);
  color: #64748B; padding: 5px 12px; border-radius: 6px;
  font-size: 12px; font-weight: 500; cursor: pointer;
  font-family: 'DM Sans', sans-serif; transition: all 0.2s;
}
.ci-select-btn:hover { color: #fff; }
.ci-select-btn.active { background: #6366F1; border-color: #6366F1; color: #fff; }
.ci-code-body { padding: 14px; display: flex; flex-direction: column; gap: 2px; }
.ci-line {
  display: flex; align-items: center; gap: 12px;
  padding: 4px 8px; border-radius: 4px;
  transition: background 0.2s;
  border-left: 2px solid transparent;
}
.ci-line-num  { font-size: 11px; color: #475569; font-family: 'DM Mono', monospace; width: 16px; flex-shrink: 0; text-align: right; }
.ci-line-code { font-size: 13px; font-family: 'DM Mono', monospace; color: #94A3B8; }
.ci-scanning  { background: rgba(99,102,241,0.1); border-left-color: #6366F1; }
.ci-executing { background: rgba(245,158,11,0.12); border-left-color: #F59E0B; }
.ci-error     { background: rgba(239,68,68,0.1); border-left-color: #EF4444; }
.ci-error .ci-line-code { color: #FCA5A5; }
.ci-controls { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.ci-mode-label { font-size: 12px; color: #94A3B8; font-family: 'DM Mono', monospace; }
.ci-output { background: #0F172A; border-radius: 10px; padding: 14px; display: flex; flex-direction: column; gap: 8px; }
.ci-output-header { font-size: 12px; font-weight: 500; font-family: 'DM Mono', monospace; }
.ci-output-body { display: flex; flex-direction: column; gap: 4px; max-height: 160px; overflow-y: auto; }
.ci-error-line { font-size: 12px; color: #FCA5A5; font-family: 'DM Mono', monospace; line-height: 1.6; }
.ci-ok-line    { font-size: 12px; color: #86EFAC; font-family: 'DM Mono', monospace; }
.ci-compiler-note   { font-size: 12px; color: #F59E0B; margin-top: 6px; line-height: 1.6; }
.ci-interpreter-note { font-size: 12px; color: #F59E0B; margin-top: 6px; line-height: 1.6; }

/* ---- LESSON 6: IDE SIM ---- */
.ide-sim-wrap {
  background: #fff;
  border: 0.5px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.ide-window { background: #1E293B; border-radius: 10px; overflow: hidden; }
.ide-toolbar {
  display: flex; gap: 4px; padding: 10px 12px;
  background: #0F172A; border-bottom: 0.5px solid rgba(255,255,255,0.07);
  flex-wrap: wrap;
}
.ide-tool-btn {
  background: rgba(255,255,255,0.06); border: 0.5px solid rgba(255,255,255,0.1);
  color: #64748B; padding: 6px 12px; border-radius: 6px;
  font-size: 12px; cursor: pointer; font-family: 'DM Sans', sans-serif;
  transition: all 0.2s;
}
.ide-tool-btn:hover { color: #fff; }
.ide-tool-btn.active { background: #6366F1; border-color: #6366F1; color: #fff; }
.ide-main { display: grid; grid-template-columns: 1fr 1fr; min-height: 180px; }
.ide-editor { padding: 14px; border-right: 0.5px solid rgba(255,255,255,0.07); display: flex; flex-direction: column; gap: 2px; }
.ide-line { display: flex; gap: 10px; align-items: center; padding: 3px 6px; border-radius: 4px; border-left: 2px solid transparent; transition: all 0.3s; }
.ide-line-num  { font-size: 11px; color: #475569; font-family: 'DM Mono', monospace; width: 14px; text-align: right; flex-shrink: 0; }
.ide-line-text { font-size: 12px; font-family: 'DM Mono', monospace; color: #94A3B8; }
.ide-line-error { border-left-color: #EF4444; background: rgba(239,68,68,0.08); }
.ide-line-error .ide-line-text { color: #FCA5A5; }
.ide-line-ugly .ide-line-text { color: #F59E0B; }
.ide-line-fixed .ide-line-text { color: #86EFAC; transition: color 0.4s; }
.ide-panel { padding: 14px; }
.ide-panel-placeholder { font-size: 12px; color: #475569; padding: 8px 0; }
.ide-feature-title { font-size: 13px; font-weight: 500; color: #fff; margin-bottom: 8px; }
.ide-feature-desc { font-size: 12px; color: #64748B; line-height: 1.65; }
.ide-run-output { margin-top: 10px; display: flex; flex-direction: column; gap: 3px; }
.ide-run-line { font-size: 11px; font-family: 'DM Mono', monospace; color: #86EFAC; }
.ide-run-line.error { color: #FCA5A5; }
.ide-error-tooltip { font-size: 11px; font-family: 'DM Mono', monospace; color: #FCA5A5; background: rgba(239,68,68,0.1); padding: 6px 10px; border-radius: 6px; margin-top: 8px; border: 0.5px solid rgba(239,68,68,0.3); }
.ide-autocomplete-demo { margin-top: 10px; }
.ide-ac-input { font-size: 13px; font-family: 'DM Mono', monospace; color: #94A3B8; padding: 6px 10px; background: rgba(255,255,255,0.04); border-radius: 4px; margin-bottom: 4px; }
.ide-ac-cursor { animation: blink 1s step-end infinite; }
@keyframes blink { 50%{ opacity:0; } }
.ide-ac-suggestion { font-size: 13px; font-family: 'DM Mono', monospace; color: #6366F1; background: rgba(99,102,241,0.12); padding: 5px 10px; border-radius: 4px; border: 0.5px solid rgba(99,102,241,0.3); }

@media (max-width: 600px) {
  .ide-main { grid-template-columns: 1fr; }
  .ide-editor { border-right: none; border-bottom: 0.5px solid rgba(255,255,255,0.07); }
}
/* ============================================
   TOPIC 5 — The Internet and its Uses
============================================ */

/* ---- L1: SORT GAME (shared across topics) ---- */
.sort-game-wrap { background:#fff; border:0.5px solid #E2E8F0; border-radius:16px; padding:22px; margin:20px 0; display:flex; flex-direction:column; gap:14px; }
.sort-game-instruction { font-size:13px; font-weight:500; color:#475569; }
.sort-items-pool { display:flex; flex-wrap:wrap; gap:8px; min-height:44px; padding:10px; background:#F8FAFC; border:1.5px dashed #CBD5E1; border-radius:10px; }
.sort-chip { background:#0F172A; color:#E2E8F0; padding:7px 13px; border-radius:8px; font-size:12px; cursor:grab; border:1.5px solid rgba(255,255,255,0.12); user-select:none; transition:all 0.15s; white-space:nowrap; display:inline-flex; align-items:center; gap:5px; }
.sort-chip:hover { border-color:#6366F1; }
.sort-chip-selected { border-color:#6366F1 !important; background:#312E81 !important; box-shadow:0 0 0 3px rgba(99,102,241,0.25); }
.sort-chip-placed { background:#1E293B; border-color:rgba(255,255,255,0.15); cursor:pointer; }
.sort-chip.sort-correct { border-color:#22C55E !important; background:rgba(34,197,94,0.15) !important; color:#86EFAC !important; }
.sort-chip.sort-wrong   { border-color:#EF4444 !important; background:rgba(239,68,68,0.15) !important; color:#FCA5A5 !important; }
.sort-buckets { display:grid; grid-template-columns:1fr 1fr; gap:12px; }
.sw-sort-buckets { display:grid; grid-template-columns:1fr 1fr; gap:12px; margin-top:8px; }
.sort-bucket { border:1.5px dashed #CBD5E1; border-radius:12px; min-height:120px; display:flex; flex-direction:column; overflow:hidden; transition:border-color 0.2s; }
.sort-bucket:hover { border-color:#6366F1; }
.sort-bucket-header { padding:10px 14px; font-size:12px; font-weight:600; text-transform:uppercase; letter-spacing:0.06em; }
.sort-bucket-internet { background:rgba(99,102,241,0.08); color:#6366F1; }
.sort-bucket-web { background:rgba(34,197,94,0.08); color:#15803D; }
.sort-bucket-sub { font-size:10px; font-weight:400; text-transform:none; letter-spacing:0; opacity:0.7; }
.sort-bucket-items { padding:8px; display:flex; flex-wrap:wrap; gap:6px; flex:1; min-height:60px; }
.sort-feedback { font-size:13px; padding:10px 14px; border-radius:8px; min-height:16px; }
.sort-feedback-correct { background:rgba(34,197,94,0.08); color:#15803D; border:0.5px solid rgba(34,197,94,0.3); }
.sort-feedback-wrong   { background:rgba(239,68,68,0.06); color:#B91C1C; border:0.5px solid rgba(239,68,68,0.2); }

/* ---- L2: PACKET INTERCEPTION SIM ---- */
.intercept-sim-wrap { background:#0F172A; border-radius:16px; padding:20px; margin:20px 0; display:flex; flex-direction:column; gap:16px; }
.intercept-browser { background:#1E293B; border-radius:12px; overflow:hidden; }
.intercept-browser-bar { background:#0F172A; padding:10px 14px; display:flex; align-items:center; gap:10px; border-bottom:0.5px solid rgba(255,255,255,0.08); flex-wrap:wrap; }
.intercept-protocol-toggle { display:flex; border:0.5px solid rgba(255,255,255,0.15); border-radius:6px; overflow:hidden; flex-shrink:0; }
.intercept-proto-btn { background:transparent; color:#64748B; border:none; padding:5px 12px; font-size:12px; cursor:pointer; font-family:'DM Sans',sans-serif; transition:all 0.2s; }
.intercept-proto-btn.active { background:#6366F1; color:#fff; }
.intercept-url-display { font-family:'DM Mono',monospace; font-size:12px; color:#EF4444; flex:1; }
.intercept-padlock { font-size:16px; }
.intercept-form { padding:20px; display:flex; flex-direction:column; gap:12px; }
.intercept-form-title { font-size:14px; font-weight:500; color:#fff; margin-bottom:4px; }
.intercept-field { display:flex; flex-direction:column; gap:4px; }
.intercept-field label { font-size:11px; color:#64748B; text-transform:uppercase; letter-spacing:0.06em; }
.intercept-input { background:rgba(255,255,255,0.06); border:0.5px solid rgba(255,255,255,0.12); border-radius:6px; padding:8px 12px; font-size:13px; color:#CBD5E1; font-family:'DM Mono',monospace; }
.intercept-submit-btn { background:#6366F1; color:#fff; border:none; padding:10px 20px; border-radius:8px; font-size:13px; font-weight:500; cursor:pointer; font-family:'DM Sans',sans-serif; margin-top:4px; transition:opacity 0.2s; }
.intercept-submit-btn:hover { opacity:0.85; }
.intercept-wire { background:#0F172A; border-radius:10px; padding:12px 14px; display:flex; align-items:center; gap:12px; min-height:54px; position:relative; overflow:hidden; }
.intercept-wire-label { font-size:10px; color:#475569; text-transform:uppercase; letter-spacing:0.06em; flex-shrink:0; }
.intercept-packet-track { flex:1; height:30px; position:relative; }
.intercept-packet { position:absolute; left:0; top:50%; transform:translateY(-50%); font-size:20px; transition:left 1.1s ease-in; }
.intercept-packet-move { left:calc(100% - 30px) !important; }
.intercept-attacker { display:flex; flex-direction:column; align-items:center; gap:2px; flex-shrink:0; }
.intercept-attacker-icon { font-size:22px; }
.intercept-attacker-label { font-size:10px; color:#64748B; }
.intercept-result { background:#1E293B; border-radius:10px; padding:14px; display:flex; flex-direction:column; gap:10px; }
.intercept-result-header { font-size:13px; font-weight:500; }
.intercept-result-bad  { color:#FCA5A5; }
.intercept-result-good { color:#86EFAC; }
.intercept-data { font-family:'DM Mono',monospace; font-size:11px; padding:10px 14px; border-radius:8px; white-space:pre; line-height:1.7; }
.intercept-data-exposed   { background:rgba(239,68,68,0.12); color:#FCA5A5; border:0.5px solid rgba(239,68,68,0.3); }
.intercept-data-encrypted { background:rgba(34,197,94,0.08); color:#86EFAC; border:0.5px solid rgba(34,197,94,0.25); }
.intercept-exposed-label { display:block; color:#EF4444; font-weight:600; margin-top:4px; }
.intercept-safe-label   { display:block; color:#22C55E; font-weight:600; margin-top:4px; }
.intercept-takeaway { background:rgba(99,102,241,0.06); border:0.5px solid rgba(99,102,241,0.25); border-radius:10px; padding:14px 16px; margin:16px 0 4px; display:flex; flex-direction:column; gap:6px; }

/* ---- L3: DNS INTRO + SEQUENCE ---- */
.dns-mission-wrap { background:#fff; border:0.5px solid #E2E8F0; border-radius:16px; padding:22px; margin:20px 0; display:flex; flex-direction:column; gap:18px; }
.dns-intro { display:flex; flex-direction:column; gap:14px; transition:opacity 0.4s; }
.dns-intro-title { font-size:13px; font-weight:500; color:#475569; }
.dns-intro-actors { display:flex; align-items:center; gap:6px; flex-wrap:wrap; }
.dns-intro-actor { display:flex; flex-direction:column; align-items:center; gap:4px; padding:10px 12px; border-radius:10px; border:1.5px solid #E2E8F0; background:#F8FAFC; transition:all 0.3s; min-width:72px; }
.dns-intro-actor.dns-actor-lit { border-color:#6366F1; background:rgba(99,102,241,0.08); box-shadow:0 0 0 3px rgba(99,102,241,0.15); transform:scale(1.06); }
.dns-intro-actor-icon { font-size:22px; }
.dns-intro-actor-label { font-size:11px; font-weight:500; color:#475569; text-align:center; }
.dns-intro-arrow { font-size:16px; color:#CBD5E1; flex-shrink:0; }
.dns-intro-msg { font-size:13px; color:#475569; line-height:1.6; background:#F8FAFC; border:0.5px solid #E2E8F0; padding:10px 14px; border-radius:8px; min-height:36px; }
.dns-intro-controls { display:flex; gap:10px; }
.dns-mission-arena { display:flex; flex-direction:column; gap:14px; }
.dns-mission-title { font-size:14px; font-weight:500; color:#1E293B; }
.dns-mission-subtitle { font-size:12px; color:#64748B; }
.dns-url-chip { font-family:'DM Mono',monospace; font-size:11px; background:#0F172A; color:#86EFAC; padding:2px 8px; border-radius:4px; }
.dns-pool-label,.dns-slots-label { font-size:11px; font-weight:500; color:#94A3B8; text-transform:uppercase; letter-spacing:0.07em; }
.dns-pool { display:flex; flex-wrap:wrap; gap:8px; min-height:44px; padding:8px; background:#F8FAFC; border:1.5px dashed #CBD5E1; border-radius:10px; }
.dns-step-chip { background:#0F172A; color:#E2E8F0; padding:7px 13px; border-radius:8px; font-size:12px; cursor:grab; border:1.5px solid rgba(255,255,255,0.1); user-select:none; transition:all 0.15s; }
.dns-step-chip:hover { border-color:#6366F1; }
.dns-step-chip.dns-chip-selected { border-color:#6366F1; background:#312E81; }
.dns-slots { display:flex; align-items:center; gap:6px; flex-wrap:wrap; }
.dns-slot { display:flex; flex-direction:column; align-items:center; gap:4px; min-width:120px; min-height:64px; padding:7px; border:1.5px dashed #CBD5E1; border-radius:10px; background:#F8FAFC; transition:all 0.2s; cursor:pointer; }
.dns-slot:hover { border-color:#6366F1; background:#EEF2FF; }
.dns-slot.dns-slot-filled  { border-style:solid; border-color:#6366F1; background:#fff; }
.dns-slot.dns-slot-correct { border-color:#22C55E !important; background:rgba(34,197,94,0.06) !important; }
.dns-slot.dns-slot-wrong   { border-color:#EF4444 !important; background:rgba(239,68,68,0.06) !important; animation:shake-slot 0.4s ease; }
@keyframes shake-slot { 0%,100%{transform:translateX(0)} 25%{transform:translateX(-4px)} 75%{transform:translateX(4px)} }
.dns-slot-num { font-size:10px; font-weight:600; color:#94A3B8; }
.dns-slot-content { font-size:11px; color:#94A3B8; text-align:center; line-height:1.4; }
.dns-slot-chip { font-size:11px; color:#1E293B; text-align:center; line-height:1.4; cursor:pointer; }
.dns-slot-chip:hover { color:#6366F1; }
.dns-slot-arrow { font-size:16px; color:#CBD5E1; flex-shrink:0; }
.dns-mission-controls { display:flex; gap:10px; flex-wrap:wrap; }
.dns-mission-feedback { font-size:13px; padding:10px 14px; border-radius:8px; min-height:16px; }
.dns-mission-feedback.correct   { background:rgba(34,197,94,0.08); color:#15803D; border:0.5px solid rgba(34,197,94,0.3); }
.dns-mission-feedback.incorrect { background:rgba(239,68,68,0.06); color:#B91C1C; border:0.5px solid rgba(239,68,68,0.2); }
.dns-mission-takeaway { background:rgba(99,102,241,0.06); border:0.5px solid rgba(99,102,241,0.25); border-radius:10px; padding:14px 16px; display:flex; flex-direction:column; gap:6px; }
.exam-takeaway-label { font-size:11px; font-weight:600; color:#6366F1; text-transform:uppercase; letter-spacing:0.07em; }
.exam-takeaway-body { font-size:13px; color:#1E293B; line-height:1.65; }

/* ---- L4: COOKIE JAR SIM ---- */
.cookie-jar-sim { display:grid; grid-template-columns:1fr 1fr; gap:16px; margin:20px 0; }
.cjs-browser-wrap { display:flex; flex-direction:column; }
.cjs-browser { background:#1E293B; border-radius:12px; overflow:hidden; border:0.5px solid rgba(255,255,255,0.08); }
.cjs-browser-bar { background:#0F172A; padding:8px 12px; display:flex; align-items:center; justify-content:space-between; border-bottom:0.5px solid rgba(255,255,255,0.08); }
.cjs-url { font-family:'DM Mono',monospace; font-size:11px; color:#22C55E; }
.cjs-close-btn { background:rgba(239,68,68,0.2); border:none; color:#FCA5A5; border-radius:4px; padding:2px 8px; font-size:11px; cursor:pointer; font-family:'DM Sans',sans-serif; }
.cjs-browser-body { padding:16px; min-height:240px; }
.cjs-site-title { font-size:15px; font-weight:500; color:#fff; margin-bottom:14px; }
.cjs-login-form { display:flex; flex-direction:column; gap:8px; }
.cjs-login-label { font-size:10px; color:#64748B; text-transform:uppercase; letter-spacing:0.06em; margin-top:4px; }
.cjs-login-input { background:rgba(255,255,255,0.06); border:0.5px solid rgba(255,255,255,0.1); border-radius:6px; padding:7px 10px; font-size:12px; color:#CBD5E1; }
.cjs-action-btn { background:#6366F1; color:#fff; border:none; padding:9px 16px; border-radius:8px; font-size:13px; cursor:pointer; font-family:'DM Sans',sans-serif; font-weight:500; margin-top:4px; }
.cjs-products { display:flex; flex-direction:column; gap:8px; margin-bottom:12px; }
.cjs-product { display:flex; align-items:center; gap:8px; background:rgba(255,255,255,0.04); border-radius:8px; padding:8px 10px; }
.cjs-prod-name { font-size:12px; color:#CBD5E1; flex:1; }
.cjs-prod-price { font-size:12px; color:#94A3B8; font-family:'DM Mono',monospace; }
.cjs-add-btn { background:rgba(99,102,241,0.2); border:0.5px solid rgba(99,102,241,0.4); color:#818CF8; padding:4px 10px; border-radius:6px; font-size:11px; cursor:pointer; font-family:'DM Sans',sans-serif; }
.cjs-add-btn:disabled { opacity:0.5; cursor:default; }
.cjs-cart-label { font-size:12px; color:#64748B; }
.cjs-storage { background:#fff; border:0.5px solid #E2E8F0; border-radius:12px; display:flex; flex-direction:column; overflow:hidden; }
.cjs-storage-title { font-size:12px; font-weight:500; color:#475569; padding:12px 14px; border-bottom:0.5px solid #E2E8F0; }
.cjs-storage-tabs { display:flex; border-bottom:0.5px solid #E2E8F0; }
.cjs-tab { flex:1; padding:8px; text-align:center; font-size:12px; color:#94A3B8; cursor:pointer; transition:all 0.2s; }
.cjs-tab.active { color:#6366F1; background:rgba(99,102,241,0.05); font-weight:500; }
.cjs-cookie-list { padding:10px; flex:1; display:flex; flex-direction:column; gap:6px; min-height:160px; overflow-y:auto; }
.cjs-empty-state { font-size:12px; color:#94A3B8; text-align:center; padding:20px 10px; }
.cjs-empty-deleted { color:#EF4444; }
.cjs-cookie-item { background:#F8FAFC; border:0.5px solid #E2E8F0; border-radius:8px; padding:8px 10px; display:flex; flex-direction:column; gap:3px; }
.cjs-cookie-name { font-size:11px; font-weight:600; color:#1E293B; font-family:'DM Mono',monospace; }
.cjs-cookie-value { font-size:10px; color:#6366F1; font-family:'DM Mono',monospace; word-break:break-all; }
.cjs-cookie-expires { font-size:10px; color:#F59E0B; }
.cjs-cookie-note { font-size:10px; color:#64748B; }
.cjs-storage-note { font-size:11px; padding:8px 12px; border-top:0.5px solid #E2E8F0; }

/* ---- L5: IP BIT COUNTER ---- */
.ip-bit-sim { background:#fff; border:0.5px solid #E2E8F0; border-radius:16px; padding:22px; margin:20px 0; display:flex; flex-direction:column; gap:16px; }
.ip-bit-tabs { display:flex; gap:8px; }
.ip-bit-tab { padding:8px 20px; border-radius:8px; border:0.5px solid #E2E8F0; background:#F8FAFC; font-size:13px; font-weight:500; color:#64748B; cursor:pointer; font-family:'DM Sans',sans-serif; transition:all 0.2s; }
.ip-bit-tab:hover { border-color:#6366F1; color:#6366F1; }
.ip-bit-tab.active { background:#6366F1; border-color:#6366F1; color:#fff; }
.ip-bit-grid { display:flex; flex-wrap:wrap; gap:3px; align-items:center; }
.ip-bit { width:18px; height:18px; border-radius:3px; font-size:9px; font-family:'DM Mono',monospace; display:flex; align-items:center; justify-content:center; font-weight:600; flex-shrink:0; }
.ip-bit-1 { background:var(--bit-color,#6366F1); color:#fff; }
.ip-bit-0 { background:#F1F5F9; color:#94A3B8; border:0.5px solid #E2E8F0; }
.ip-bit-gap { width:6px; height:18px; flex-shrink:0; }
.ip-bit-count { font-size:11px; color:#94A3B8; margin-top:4px; }
.ip-addr-label { font-size:11px; font-weight:500; margin-bottom:4px; }
.ip-addr-value { font-family:'DM Mono',monospace; font-size:15px; color:#1E293B; background:#F1F5F9; padding:10px 14px; border-radius:8px; word-break:break-all; }
.ip-bit-facts { display:flex; flex-direction:column; gap:8px; }
.ip-fact { display:flex; gap:10px; font-size:13px; align-items:baseline; }
.ip-fact-key { color:#64748B; min-width:76px; font-weight:500; flex-shrink:0; }
.ip-fact-val { color:#1E293B; }
.ip-fact-note { font-size:12px; color:#64748B; background:#F8FAFC; border:0.5px solid #E2E8F0; padding:8px 12px; border-radius:8px; line-height:1.6; }

/* ---- L6: MAC SCANNER ---- */
.mac-scanner-sim { background:#fff; border:0.5px solid #E2E8F0; border-radius:16px; padding:22px; margin:20px 0; display:flex; flex-direction:column; gap:16px; }
.mac-scanner-header { display:flex; align-items:center; justify-content:space-between; gap:12px; }
.mac-scanner-title { font-size:14px; font-weight:500; color:#1E293B; }
.mac-devices-list { display:flex; flex-direction:column; gap:8px; min-height:40px; }
.mac-empty { font-size:13px; color:#94A3B8; }
.mac-device-row { display:flex; align-items:center; gap:14px; padding:12px 14px; background:#F8FAFC; border:0.5px solid #E2E8F0; border-radius:10px; transition:all 0.3s; }
.mac-device-row.mac-dev-highlighted { border-color:#6366F1; background:rgba(99,102,241,0.05); }
.mac-dev-icon { font-size:22px; flex-shrink:0; }
.mac-dev-info { flex:1; }
.mac-dev-name { font-size:13px; font-weight:500; color:#1E293B; }
.mac-dev-ip { font-size:11px; color:#64748B; font-family:'DM Mono',monospace; }
.mac-dev-addr { font-family:'DM Mono',monospace; font-size:13px; display:flex; align-items:center; }
.mac-oui { color:#6366F1; font-weight:600; background:rgba(99,102,241,0.1); padding:2px 4px; border-radius:4px; }
.mac-colon { color:#94A3B8; padding:0 1px; }
.mac-serial-part { color:#475569; }
.mac-challenge { background:#F8FAFC; border:0.5px solid #E2E8F0; border-radius:12px; padding:16px; display:flex; flex-direction:column; gap:12px; }
.mac-challenge-title { font-size:13px; font-weight:500; color:#1E293B; }
.mac-challenge-hint { font-size:12px; color:#64748B; }
.mac-challenge-options { display:flex; flex-direction:column; gap:8px; }
.mac-challenge-btn { background:#fff; border:0.5px solid #E2E8F0; padding:10px 14px; border-radius:8px; font-size:13px; cursor:pointer; font-family:'DM Sans',sans-serif; text-align:left; color:#1E293B; transition:all 0.2s; }
.mac-challenge-btn:hover:not(:disabled) { border-color:#6366F1; background:rgba(99,102,241,0.04); }
.mac-challenge-feedback { font-size:13px; padding:10px 14px; border-radius:8px; min-height:16px; }
.mac-challenge-feedback.correct   { background:rgba(34,197,94,0.08); color:#15803D; border:0.5px solid rgba(34,197,94,0.3); }
.mac-challenge-feedback.incorrect { background:rgba(239,68,68,0.06); color:#B91C1C; border:0.5px solid rgba(239,68,68,0.2); }

/* ---- L7: BLOCKCHAIN TAMPER ---- */
.bc-tamper-wrap { background:#fff; border:0.5px solid #E2E8F0; border-radius:16px; padding:22px; margin:20px 0; display:flex; flex-direction:column; gap:16px; }
.bc-tamper-header { display:flex; align-items:center; justify-content:space-between; gap:12px; flex-wrap:wrap; }
.bc-tamper-title { font-size:13px; font-weight:500; color:#475569; }
.bc-chain-status { display:flex; align-items:center; }
.bc-status-indicator { display:flex; align-items:center; gap:8px; font-size:13px; font-weight:500; }
.bc-status-dot { width:8px; height:8px; border-radius:50%; background:currentColor; flex-shrink:0; }
.bc-status-valid   { color:#15803D; }
.bc-status-invalid { color:#DC2626; }
.bc-chain-display { display:flex; align-items:flex-start; gap:10px; overflow-x:auto; padding-bottom:6px; }
.bc-tamper-block { background:#F8FAFC; border:1.5px solid #E2E8F0; border-radius:12px; padding:14px; min-width:175px; display:flex; flex-direction:column; gap:6px; transition:all 0.3s; flex-shrink:0; }
.bc-tamper-block-modified { border-color:#F59E0B; background:rgba(245,158,11,0.04); }
.bc-tamper-block-broken   { border-color:#EF4444; background:rgba(239,68,68,0.04); }
.bc-tb-header { display:flex; align-items:center; justify-content:space-between; margin-bottom:4px; }
.bc-tb-num { font-size:12px; font-weight:600; color:#475569; }
.bc-tb-broken-badge { font-size:10px; color:#EF4444; font-weight:600; background:rgba(239,68,68,0.1); padding:2px 6px; border-radius:4px; }
.bc-tb-row { display:flex; gap:8px; align-items:baseline; }
.bc-tb-key { font-size:10px; color:#94A3B8; min-width:64px; flex-shrink:0; text-transform:uppercase; letter-spacing:0.05em; }
.bc-tb-val { font-size:12px; color:#1E293B; }
.bc-tb-mono { font-family:'DM Mono',monospace; font-size:11px; }
.bc-tb-hash { color:#64748B; }
.bc-hash-changed { color:#F59E0B; font-weight:500; }
.bc-tb-divider { height:0.5px; background:#E2E8F0; margin:4px 0; }
.bc-tb-amount-row { align-items:center; }
.bc-amount-edit { color:#6366F1; font-weight:500; font-size:13px; cursor:pointer; text-decoration:underline dotted; transition:color 0.15s; }
.bc-amount-edit:hover { color:#4F46E5; }
.bc-amount-input { font-family:'DM Mono',monospace; font-size:13px; color:#1E293B; border:1.5px solid #6366F1; border-radius:4px; padding:2px 6px; width:80px; outline:none; }
.bc-tb-tampered-tag { font-size:10px; color:#F59E0B; font-weight:600; background:rgba(245,158,11,0.15); padding:2px 6px; border-radius:4px; margin-left:4px; }
.bc-chain-arrow { font-size:22px; color:#CBD5E1; padding-top:30px; flex-shrink:0; transition:color 0.3s; }
.bc-arrow-broken { color:#EF4444; }
.bc-tamper-explanation { font-size:13px; color:#475569; line-height:1.65; background:#F8FAFC; border:0.5px solid #E2E8F0; border-radius:8px; padding:12px 14px; }
.bc-tamper-controls { display:flex; gap:10px; }

/* ---- L8: CYBER DEFENCE DASHBOARD ---- */
.cdd-wrap { background:#0F172A; border-radius:16px; padding:22px; margin:20px 0; display:flex; flex-direction:column; gap:18px; min-height:340px; }
.cdd-hud { display:flex; align-items:center; justify-content:space-between; gap:16px; padding-bottom:16px; border-bottom:0.5px solid rgba(255,255,255,0.08); }
.cdd-hud-left { display:flex; flex-direction:column; gap:6px; flex:1; }
.cdd-hud-right { display:flex; flex-direction:column; align-items:flex-end; gap:4px; }
.cdd-hud-label { font-size:10px; color:#64748B; text-transform:uppercase; letter-spacing:0.08em; font-weight:500; }
.cdd-score-bar-wrap { width:100%; max-width:220px; height:6px; background:rgba(255,255,255,0.1); border-radius:3px; overflow:hidden; }
.cdd-score-bar { height:100%; width:0%; background:#22C55E; border-radius:3px; transition:width 0.4s,background 0.4s; }
.cdd-score-num { font-size:20px; font-weight:500; color:#fff; font-family:'DM Mono',monospace; }
.cdd-attack-counter { font-size:18px; font-weight:500; color:#fff; font-family:'DM Mono',monospace; }
.cdd-intro { display:flex; flex-direction:column; align-items:center; gap:14px; padding:16px 0; text-align:center; }
.cdd-intro-icon { font-size:44px; }
.cdd-intro-title { font-size:17px; font-weight:500; color:#fff; }
.cdd-intro-body { font-size:13px; color:#94A3B8; line-height:1.65; max-width:440px; }
.cdd-attack-screen { display:flex; flex-direction:column; gap:14px; }
.cdd-attack-alert { background:rgba(239,68,68,0.08); border:0.5px solid rgba(239,68,68,0.25); border-radius:12px; overflow:hidden; }
.cdd-alert-bar { display:flex; align-items:center; gap:10px; padding:10px 16px; background:rgba(239,68,68,0.15); border-bottom:0.5px solid rgba(239,68,68,0.2); }
.cdd-alert-icon { font-size:18px; }
.cdd-alert-type { font-size:12px; font-weight:600; color:#FCA5A5; text-transform:uppercase; letter-spacing:0.06em; }
.cdd-attack-description { padding:14px 16px; font-size:13px; color:#CBD5E1; line-height:1.7; }
.cdd-attack-question { padding:0 16px 12px; font-size:12px; color:#64748B; font-weight:500; }
.cdd-defences { display:grid; grid-template-columns:1fr 1fr; gap:8px; }
.cdd-defence-btn { background:rgba(255,255,255,0.05); border:0.5px solid rgba(255,255,255,0.12); color:#CBD5E1; padding:11px 13px; border-radius:10px; font-size:13px; cursor:pointer; font-family:'DM Sans',sans-serif; text-align:left; transition:all 0.2s; line-height:1.4; }
.cdd-defence-btn:hover:not(:disabled) { background:rgba(99,102,241,0.15); border-color:rgba(99,102,241,0.4); color:#fff; }
.cdd-defence-btn:disabled { cursor:default; }
.cdd-btn-correct { background:rgba(34,197,94,0.15) !important; border-color:rgba(34,197,94,0.5) !important; color:#86EFAC !important; }
.cdd-btn-wrong   { background:rgba(239,68,68,0.12) !important; border-color:rgba(239,68,68,0.4) !important; color:#FCA5A5 !important; }
.cdd-attack-feedback { font-size:13px; color:#94A3B8; line-height:1.65; padding:10px 14px; border-radius:8px; min-height:18px; }
.cdd-attack-feedback.correct   { background:rgba(34,197,94,0.08); color:#86EFAC; border:0.5px solid rgba(34,197,94,0.2); }
.cdd-attack-feedback.incorrect { background:rgba(239,68,68,0.06); color:#FCA5A5; border:0.5px solid rgba(239,68,68,0.2); }
.cdd-correct-label { display:block; margin-top:6px; font-weight:500; color:#86EFAC; }
.cdd-result-screen { display:flex; flex-direction:column; align-items:center; gap:14px; padding:20px 0; text-align:center; }
.cdd-result-icon  { font-size:48px; }
.cdd-result-title { font-size:19px; font-weight:500; color:#fff; }
.cdd-result-body  { font-size:13px; color:#94A3B8; line-height:1.65; max-width:420px; }
.cdd-result-score { font-size:14px; font-weight:500; color:#6366F1; font-family:'DM Mono',monospace; }

/* ============================================
   CHAPTER 3 + 4.1 REDESIGN
============================================ */

/* ---- PREDICT → OBSERVE → EXPLAIN ---- */
.predict-strip { background:#F8FAFC; border:1.5px solid #E2E8F0; border-radius:14px; padding:18px 20px; margin:16px 0; display:flex; flex-direction:column; gap:12px; }
.predict-label { font-size:11px; font-weight:600; color:#6366F1; text-transform:uppercase; letter-spacing:0.07em; }
.predict-question { font-size:14px; color:#1E293B; line-height:1.6; font-weight:500; }
.predict-options { display:flex; flex-wrap:wrap; gap:8px; }
.predict-btn { background:#fff; border:1.5px solid #E2E8F0; border-radius:8px; padding:9px 16px; font-size:13px; cursor:pointer; font-family:'DM Sans',sans-serif; color:#1E293B; transition:all 0.2s; }
.predict-btn:hover:not(:disabled) { border-color:#6366F1; color:#6366F1; }
.predict-btn:disabled { opacity:0.6; cursor:default; }
.predict-result { padding:12px 14px; border-radius:8px; font-size:13px; line-height:1.6; }
.predict-correct { background:rgba(34,197,94,0.07); color:#15803D; border:0.5px solid rgba(34,197,94,0.3); }
.predict-wrong   { background:rgba(239,68,68,0.06); color:#B91C1C; border:0.5px solid rgba(239,68,68,0.2); }

/* ---- CPU ASSEMBLY ---- */
.cpu-build-wrap { background:#fff; border:0.5px solid #E2E8F0; border-radius:16px; padding:22px; margin:16px 0; display:flex; flex-direction:column; gap:14px; }
.cpu-build-pool { display:flex; flex-wrap:wrap; gap:8px; min-height:44px; padding:10px; background:#F8FAFC; border:1.5px dashed #CBD5E1; border-radius:10px; }
.cpu-chip { background:#0F172A; color:#E2E8F0; padding:7px 12px; border-radius:7px; font-size:12px; cursor:grab; border:1.5px solid var(--chip-color,rgba(255,255,255,0.1)); user-select:none; transition:all 0.15s; white-space:nowrap; }
.cpu-chip:hover { box-shadow:0 0 0 2px var(--chip-color,#6366F1); }
.cpu-chip.cpu-chip-selected { box-shadow:0 0 0 3px var(--chip-color,#6366F1); background:#1E293B; }
.cpu-build-diagram { display:flex; justify-content:center; margin-top:4px; }
.cpu-build-outer { background:#F1F5F9; border:2px solid #CBD5E1; border-radius:14px; padding:16px 20px; min-width:320px; width:100%; max-width:520px; }
.cpu-build-label { font-size:11px; font-weight:600; color:#64748B; text-align:center; text-transform:uppercase; letter-spacing:0.06em; margin-bottom:12px; }
.cpu-build-grid { display:grid; grid-template-columns:1fr 1fr 1fr 1fr; gap:8px; }
.cpu-slot-wide { grid-column:1/-1; }
.cpu-slot-wrap { display:flex; flex-direction:column; gap:3px; }
.cpu-slot-label-top { font-size:9px; color:#94A3B8; text-align:center; text-transform:uppercase; letter-spacing:0.05em; }
.cpu-build-slot { background:#fff; border:1.5px dashed #CBD5E1; border-radius:8px; min-height:40px; display:flex; align-items:center; justify-content:center; padding:4px 6px; cursor:pointer; transition:all 0.2s; text-align:center; }
.cpu-build-slot:hover { border-color:#6366F1; background:#EEF2FF; }
.cpu-slot-chip { font-size:10px; padding:3px 6px; border-radius:5px; border:1px solid; cursor:pointer; text-align:center; line-height:1.3; }
.cpu-slot-label { font-size:10px; color:#94A3B8; text-align:center; }
.cpu-build-slot.cpu-slot-correct { border-color:#22C55E; background:rgba(34,197,94,0.06); border-style:solid; }
.cpu-build-slot.cpu-slot-wrong   { border-color:#EF4444; background:rgba(239,68,68,0.06); border-style:solid; animation:shake-slot 0.4s ease; }
.cpu-build-feedback { font-size:13px; padding:10px 14px; border-radius:8px; min-height:16px; }
.cpu-build-feedback.correct   { background:rgba(34,197,94,0.08); color:#15803D; border:0.5px solid rgba(34,197,94,0.3); }
.cpu-build-feedback.incorrect { background:rgba(239,68,68,0.06); color:#B91C1C; border:0.5px solid rgba(239,68,68,0.2); }

/* ---- CPU RUN MODE ---- */
.cpu-run-inner { display:grid; grid-template-columns:180px 80px 1fr; gap:12px; align-items:start; }
.cpu-run-section-label { font-size:10px; color:#94A3B8; text-transform:uppercase; letter-spacing:0.07em; margin-bottom:6px; font-weight:600; }
.cpu-run-ram { background:#F1F5F9; border-radius:10px; padding:10px; }
.cpu-run-ram-rows { display:flex; flex-direction:column; gap:4px; }
.cpu-run-ram-row { display:flex; gap:6px; font-family:'DM Mono',monospace; font-size:11px; }
.cr-addr { color:#94A3B8; min-width:32px; }
.cr-val  { color:#1E293B; }
.cpu-run-buses { display:flex; flex-direction:column; gap:8px; padding-top:24px; }
.cpu-run-bus { border:1px solid #E2E8F0; border-radius:6px; padding:4px 6px; transition:border-color 0.3s; }
.cr-bus-label { font-size:9px; color:#94A3B8; text-transform:uppercase; letter-spacing:0.05em; }
.cr-bus-line { height:6px; background:#F1F5F9; border-radius:3px; margin-top:3px; position:relative; overflow:hidden; }
.cr-addr-signal,.cr-data-signal { position:absolute; top:0; height:100%; width:0; background:#6366F1; border-radius:3px; }
.cpu-run-regs { display:flex; flex-direction:column; gap:6px; }
.cr-reg { background:#fff; border:0.5px solid #E2E8F0; border-radius:8px; padding:6px 10px; display:flex; align-items:center; justify-content:space-between; transition:box-shadow 0.3s; }
.cr-reg-name { font-size:10px; color:#94A3B8; font-weight:600; text-transform:uppercase; }
.cr-reg-val  { font-family:'DM Mono',monospace; font-size:12px; color:#1E293B; font-weight:500; }
.cr-unit { background:#1E293B; color:#E2E8F0; border-radius:7px; padding:5px 10px; font-size:11px; font-weight:600; text-align:center; transition:background 0.3s; }
.fde-cpu { background:#F1F5F9; border-radius:12px; padding:12px; display:flex; flex-direction:column; gap:6px; }
.fde-cpu-label { font-size:10px; color:#94A3B8; text-transform:uppercase; letter-spacing:0.07em; font-weight:600; margin-bottom:2px; }
.fde-unit { background:#1E293B; color:#E2E8F0; border-radius:7px; padding:5px 10px; font-size:11px; font-weight:600; text-align:center; transition:background 0.3s; }

/* ---- STORAGE ---- */
.storage-mech-card { background:#fff; border:0.5px solid #E2E8F0; border-radius:12px; padding:16px; display:flex; flex-direction:column; gap:10px; }
.storage-mech-header { display:flex; align-items:center; gap:10px; }
.storage-mech-icon { font-size:24px; }
.storage-mech-name { font-size:15px; font-weight:500; }
.storage-mech-body { font-size:13px; color:#475569; line-height:1.7; }
.storage-mech-specs { display:flex; flex-direction:column; gap:5px; }
.storage-spec { display:flex; gap:10px; font-size:12px; }
.storage-spec-k { color:#94A3B8; min-width:100px; font-weight:500; flex-shrink:0; }
.storage-spec-v { color:#1E293B; }
.storage-mech-bestfor { font-size:12px; color:#6366F1; font-weight:500; background:rgba(99,102,241,0.06); padding:7px 10px; border-radius:7px; }

/* ---- SCENARIO CARDS (cloud, storage, cpu) ---- */
.cloud-scen-card { background:#fff; border:0.5px solid #E2E8F0; border-radius:12px; padding:16px; margin-bottom:12px; display:flex; flex-direction:column; gap:10px; transition:border-color 0.3s; }
.cloud-scen-card.scen-complete { border-color:#22C55E; }
.cloud-scen-header { display:flex; align-items:center; gap:10px; }
.cloud-scen-icon { font-size:22px; }
.cloud-scen-title { font-size:14px; font-weight:500; color:#1E293B; }
.cloud-scen-desc { font-size:13px; color:#475569; line-height:1.6; }
.cloud-scen-choices { display:flex; flex-wrap:wrap; gap:8px; }
.cloud-scen-reasons { display:flex; flex-direction:column; gap:6px; }
.cloud-scen-result { font-size:13px; padding:10px 14px; border-radius:8px; line-height:1.6; }
.cloud-scen-result.pass { background:rgba(34,197,94,0.08); color:#15803D; border:0.5px solid rgba(34,197,94,0.3); }
.cloud-scen-result.fail { background:rgba(239,68,68,0.06); color:#B91C1C; border:0.5px solid rgba(239,68,68,0.2); }
.cloud-scen-result.warn { background:rgba(245,158,11,0.08); color:#92400E; border:0.5px solid rgba(245,158,11,0.3); }
.cpu-scen-card { background:#F8FAFC; border:0.5px solid #E2E8F0; border-radius:12px; padding:14px; margin-bottom:10px; transition:border-color 0.3s; }
.cpu-scen-card.scen-complete { border-color:#22C55E; }
.cpu-scen-title { font-size:14px; font-weight:500; color:#1E293B; margin-bottom:4px; }
.cpu-scen-desc  { font-size:13px; color:#475569; line-height:1.6; margin-bottom:6px; }
.cpu-scen-req   { font-size:12px; color:#6366F1; background:rgba(99,102,241,0.06); padding:5px 10px; border-radius:6px; }
.cpu-scen-result { font-size:13px; padding:9px 13px; border-radius:8px; margin-top:8px; line-height:1.6; }
.cpu-scen-result.pass { background:rgba(34,197,94,0.08); color:#15803D; border:0.5px solid rgba(34,197,94,0.3); }
.cpu-scen-result.fail { background:rgba(239,68,68,0.06); color:#B91C1C; border:0.5px solid rgba(239,68,68,0.2); }

/* ---- VM JUGGLER ---- */
.vm-speed-gauge { background:#F8FAFC; border:0.5px solid #E2E8F0; border-radius:10px; padding:12px 14px; margin-top:10px; display:flex; flex-direction:column; gap:6px; }
.vm-gauge-label { font-size:11px; color:#64748B; font-weight:500; }
.vm-gauge-track { height:8px; background:#E2E8F0; border-radius:4px; overflow:hidden; }
.vm-gauge-fill { height:100%; border-radius:4px; transition:width 0.4s,background 0.4s; }
.vm-gauge-pct { font-size:14px; font-weight:500; font-family:'DM Mono',monospace; }
.vm-thrash-warning { font-size:12px; color:#EF4444; font-weight:500; }
.vm-diagram { display:flex; flex-direction:column; gap:8px; margin-top:10px; }
.vm-section { background:#fff; border:0.5px solid #E2E8F0; border-radius:10px; overflow:hidden; }
.vm-section-header { padding:8px 12px; font-size:11px; font-weight:600; text-transform:uppercase; letter-spacing:0.06em; }
.ram-header { background:rgba(99,102,241,0.08); color:#6366F1; }
.vm-header  { background:rgba(239,68,68,0.08); color:#DC2626; }
.vm-slots { display:flex; flex-wrap:wrap; gap:6px; padding:8px 12px; }
.vm-slot { padding:6px 12px; border-radius:6px; font-size:12px; font-weight:500; }
.vm-slot.filled  { background:#EEF2FF; color:#6366F1; border:0.5px solid rgba(99,102,241,0.3); }
.vm-slot.empty   { background:#F8FAFC; color:#CBD5E1; border:1px dashed #E2E8F0; }
.vm-slot.virtual { background:rgba(239,68,68,0.08); color:#DC2626; border:0.5px solid rgba(239,68,68,0.25); }
.vm-overflow-arrow { font-size:12px; color:#EF4444; font-weight:500; text-align:center; }
.vm-slow-tag { font-size:10px; }
.vm-chain-chip { background:#0F172A; color:#E2E8F0; padding:8px 14px; border-radius:8px; font-size:12px; cursor:grab; border:1.5px solid rgba(255,255,255,0.1); user-select:none; transition:all 0.15s; }
.vm-chain-chip:hover { border-color:#6366F1; }
.vm-chain-chip.dns-chip-selected { border-color:#6366F1; background:#312E81; }
.vm-chain-slots { display:flex; flex-direction:column; gap:8px; }
.memory-predict-btn { background:#fff; border:1.5px solid #E2E8F0; border-radius:8px; padding:9px 16px; font-size:13px; cursor:pointer; font-family:'DM Sans',sans-serif; color:#1E293B; transition:all 0.2s; }
.memory-predict-btn:hover:not(:disabled) { border-color:#6366F1; color:#6366F1; }
.memory-predict-btn:disabled { opacity:0.6; cursor:default; }
.memory-observe-note { font-size:13px; padding:10px 14px; border-radius:8px; }
.memory-observe-note.correct   { background:rgba(34,197,94,0.07); color:#15803D; }
.memory-observe-note.incorrect { background:rgba(239,68,68,0.06); color:#B91C1C; }

/* ---- BOOT SEQUENCE ---- */
.boot-seq-wrap { background:#F8FAFC; border:0.5px solid #E2E8F0; border-radius:12px; padding:14px; margin-top:12px; }
.boot-seq-steps { display:flex; align-items:center; gap:6px; flex-wrap:wrap; }
.boot-step { display:flex; align-items:center; gap:4px; }
.boot-step-label { padding:6px 12px; border-radius:7px; border:1.5px solid; font-size:12px; font-weight:500; opacity:0.35; transition:opacity 0.3s; }
.boot-step.boot-step-active .boot-step-label { opacity:1; }
.boot-step-arrow { font-size:14px; color:#CBD5E1; }
.boot-step-end { font-size:20px; opacity:0.3; }

/* ---- INPUT/OUTPUT REFERENCE GRIDS ---- */
.io-device-reference-grid { display:flex; flex-wrap:wrap; gap:7px; margin-bottom:10px; }
.io-ref-chip { background:#F1F5F9; border:1.5px solid #E2E8F0; border-radius:8px; padding:7px 12px; font-size:12px; font-weight:500; color:#475569; cursor:pointer; transition:all 0.18s; white-space:nowrap; user-select:none; }
.io-ref-chip:hover { border-color:#6366F1; color:#6366F1; background:#EEF2FF; }
.io-ref-chip.io-ref-active { border-color:#6366F1; background:#6366F1; color:#fff; }
.io-device-reference-detail { background:#F8FAFC; border:0.5px solid #E2E8F0; border-radius:10px; padding:14px 16px; min-height:60px; margin-bottom:8px; }
.io-ref-detail-header { display:flex; align-items:center; gap:10px; margin-bottom:8px; }
.io-ref-detail-icon { font-size:22px; }
.io-ref-detail-name { font-size:14px; font-weight:600; color:#1E293B; }
.io-ref-detail-how { font-size:13px; color:#475569; line-height:1.7; }

/* ---- INPUT/OUTPUT CHALLENGE CARDS ---- */
.io-challenge-card { background:#fff; border:0.5px solid #E2E8F0; border-radius:12px; padding:14px; margin-bottom:10px; display:flex; flex-direction:column; gap:8px; transition:border-color 0.3s; }
.io-challenge-card.ioc-complete { border-color:#22C55E; }
.io-challenge-scenario { font-size:13px; color:#1E293B; line-height:1.65; font-weight:500; }
.io-challenge-predict { font-size:12px; color:#64748B; margin-bottom:4px; }
.io-challenge-input { width:100%; padding:8px 12px; border:1.5px solid #E2E8F0; border-radius:8px; font-size:13px; font-family:'DM Sans',sans-serif; color:#1E293B; outline:none; transition:border-color 0.2s; box-sizing:border-box; }
.io-challenge-input:focus { border-color:#6366F1; }
.io-challenge-choices { display:flex; flex-direction:column; gap:6px; }
.io-challenge-feedback { font-size:13px; padding:10px 14px; border-radius:8px; line-height:1.65; }
.io-challenge-feedback.correct   { background:rgba(34,197,94,0.07); color:#15803D; border:0.5px solid rgba(34,197,94,0.3); }
.io-challenge-feedback.incorrect { background:rgba(239,68,68,0.06); color:#B91C1C; border:0.5px solid rgba(239,68,68,0.2); }

/* ---- SENSOR REFERENCE + POOL ---- */
.sensor-reference-wrap { background:#fff; border:0.5px solid #E2E8F0; border-radius:14px; padding:16px; margin-bottom:16px; }
.sensor-reference-grid { display:grid; grid-template-columns:repeat(4,1fr); gap:8px; margin-top:8px; }
.sensor-ref-card { background:#F8FAFC; border:0.5px solid #E2E8F0; border-radius:9px; padding:10px 8px; text-align:center; display:flex; flex-direction:column; gap:3px; }
.sensor-ref-icon { font-size:18px; }
.sensor-ref-name { font-size:11px; font-weight:600; color:#1E293B; }
.sensor-ref-measures { font-size:10px; color:#64748B; line-height:1.4; }
.sensor-pool { display:flex; flex-wrap:wrap; gap:7px; padding:10px; background:#F8FAFC; border:1.5px dashed #CBD5E1; border-radius:10px; min-height:40px; }
.sensor-pool-chip { background:#0F172A; color:#E2E8F0; padding:6px 11px; border-radius:7px; font-size:12px; cursor:grab; border:1.5px solid rgba(255,255,255,0.1); user-select:none; transition:all 0.15s; white-space:nowrap; }
.sensor-pool-chip:hover { border-color:#6366F1; }
.sensor-pool-chip.dns-chip-selected { border-color:#6366F1; background:#312E81; }
.sensor-scen-card { background:#fff; border:0.5px solid #E2E8F0; border-radius:12px; padding:14px; margin-bottom:10px; display:flex; flex-direction:column; gap:8px; transition:border-color 0.3s; }
.sensor-scen-card.scen-complete { border-color:#22C55E; }
.sensor-scen-header { display:flex; align-items:center; gap:8px; font-size:14px; font-weight:500; color:#1E293B; }
.sensor-scen-title { font-size:14px; font-weight:500; }
.sensor-scen-desc { font-size:13px; color:#475569; line-height:1.6; }
.sensor-scen-slots { display:flex; align-items:center; gap:8px; flex-wrap:wrap; }
.sensor-scen-slot { background:#F8FAFC; border:1.5px dashed #CBD5E1; border-radius:8px; padding:8px 14px; font-size:12px; color:#94A3B8; cursor:pointer; min-width:100px; text-align:center; transition:all 0.2s; }
.sensor-scen-slot.sensor-slot-filled { border-style:solid; border-color:#6366F1; color:#1E293B; background:#EEF2FF; }
.sensor-scen-result { font-size:13px; padding:10px 14px; border-radius:8px; line-height:1.6; }
.sensor-scen-result.pass { background:rgba(34,197,94,0.08); color:#15803D; border:0.5px solid rgba(34,197,94,0.3); }
.sensor-scen-result.fail { background:rgba(239,68,68,0.06); color:#B91C1C; border:0.5px solid rgba(239,68,68,0.2); }

/* ---- NETWORK BUILDER ---- */
.net-comp-chip { background:#0F172A; color:#E2E8F0; padding:8px 13px; border-radius:8px; font-size:12px; cursor:grab; border:1.5px solid rgba(255,255,255,0.1); user-select:none; transition:all 0.15s; white-space:nowrap; }
.net-comp-chip:hover { border-color:#6366F1; }
.net-comp-chip.dns-chip-selected { border-color:#6366F1; background:#312E81; }
.net-topology-row { display:flex; align-items:center; gap:6px; flex-wrap:wrap; padding:12px 0; }
.net-drop-slot { min-width:110px; min-height:54px; border:1.5px dashed #CBD5E1; border-radius:10px; display:flex; align-items:center; justify-content:center; padding:8px; background:#F8FAFC; cursor:pointer; transition:all 0.2s; font-size:12px; color:#94A3B8; text-align:center; }
.net-drop-slot:hover { border-color:#6366F1; background:#EEF2FF; }
.net-drop-slot.cpu-slot-correct { border-color:#22C55E; background:rgba(34,197,94,0.06); border-style:solid; }
.net-drop-slot.cpu-slot-wrong   { border-color:#EF4444; background:rgba(239,68,68,0.06); border-style:solid; animation:shake-slot 0.4s ease; }
.net-placed-chip { background:#6366F1; color:#fff; padding:6px 10px; border-radius:6px; font-size:12px; cursor:pointer; text-align:center; }
.net-placed-chip:hover { background:#4F46E5; }
.net-topo-arrow { font-size:18px; color:#CBD5E1; flex-shrink:0; }
.net-journey-nodes { display:flex; align-items:center; gap:6px; flex-wrap:wrap; padding:14px 0; }
.net-journey-node { background:#F8FAFC; border:1.5px solid #E2E8F0; border-radius:10px; padding:10px 12px; font-size:12px; text-align:center; transition:all 0.3s; min-width:60px; }
.net-journey-node.net-node-active { border-color:#6366F1; background:#EEF2FF; color:#6366F1; font-weight:500; transform:scale(1.06); }
.net-journey-arrow { font-size:18px; color:#CBD5E1; flex-shrink:0; transition:color 0.3s; }

/* ---- OS FUNCTIONS ---- */
.os-sim-wrap { background:#fff; border:0.5px solid #E2E8F0; border-radius:14px; padding:16px; display:flex; flex-direction:column; gap:12px; }
.os-functions-grid { display:grid; grid-template-columns:repeat(4,1fr); gap:8px; }
.os-func-card { background:#F8FAFC; border:1.5px solid #E2E8F0; border-radius:10px; padding:12px 10px; text-align:center; cursor:pointer; transition:all 0.2s; }
.os-func-card:hover { border-color:#6366F1; background:rgba(99,102,241,0.04); }
.os-func-card.active { border-color:#6366F1; background:rgba(99,102,241,0.08); }
.osf-icon { font-size:20px; margin-bottom:4px; }
.osf-name { font-size:11px; font-weight:500; color:#475569; line-height:1.3; }
.os-function-detail { background:#F8FAFC; border:0.5px solid #E2E8F0; border-radius:10px; padding:14px; }

/* ---- TRACE TABLE ---- */
.trace-table-wrap { background:#fff; border:0.5px solid #E2E8F0; border-radius:14px; padding:16px; margin-top:12px; }
.trace-tbl { width:100%; border-collapse:collapse; font-size:12px; }
.trace-tbl th { background:#F1F5F9; color:#475569; font-weight:600; padding:8px 10px; text-align:left; border:0.5px solid #E2E8F0; }
.trace-tbl td { padding:6px 8px; border:0.5px solid #E2E8F0; }
.trace-stage-cell { font-size:11px; color:#64748B; font-weight:500; white-space:nowrap; }
.trace-input { width:100%; padding:4px 7px; border:1.5px solid #E2E8F0; border-radius:5px; font-size:12px; font-family:'DM Mono',monospace; outline:none; transition:border-color 0.2s; box-sizing:border-box; }
.trace-input:focus { border-color:#6366F1; }
.trace-input.correct   { border-color:#22C55E; background:rgba(34,197,94,0.06); }
.trace-input.incorrect { border-color:#EF4444; background:rgba(239,68,68,0.06); }

/* ---- RESPONSIVE ---- */
@media (max-width:600px) {
  .cpu-build-grid { grid-template-columns:1fr 1fr; }
  .cpu-slot-wide { grid-column:1/-1; }
  .sw-sort-buckets { grid-template-columns:1fr; }
  .sort-buckets { grid-template-columns:1fr; }
  .os-functions-grid { grid-template-columns:repeat(2,1fr); }
  .sensor-reference-grid { grid-template-columns:repeat(2,1fr); }
  .net-topology-row { flex-direction:column; align-items:stretch; }
  .net-journey-nodes { flex-direction:column; align-items:stretch; }
  .cpu-run-inner { grid-template-columns:1fr; }
  .cdd-defences { grid-template-columns:1fr; }
  .cookie-jar-sim { grid-template-columns:1fr; }
  .dns-slots { flex-direction:column; align-items:stretch; }
  .dns-slot-arrow { display:none; }
  .ip-bit { width:14px; height:14px; font-size:7px; }
}

/* ============================================
   TEACH-THEN-TEST CARDS (Input/Output devices)
   Decision cards (Storage/Cloud scenarios)
============================================ */

/* ---- TEACH-THEN-TEST CARD ---- */
.teach-then-test-card { background:#fff; border:0.5px solid #E2E8F0; border-radius:16px; overflow:hidden; margin-bottom:20px; transition:border-color 0.3s; }
.teach-then-test-card.ttt-complete { border-color:#22C55E; }

/* Teach panel — dark, always visible */
.ttt-teach-panel { background:#0F172A; padding:20px 22px; display:flex; flex-direction:column; gap:12px; }
.ttt-device-header { display:flex; align-items:center; gap:14px; }
.ttt-device-badge { width:44px; height:44px; border-radius:10px; background:rgba(99,102,241,0.2); border:1.5px solid rgba(99,102,241,0.35); display:flex; align-items:center; justify-content:center; font-size:22px; flex-shrink:0; }
.ttt-device-info { display:flex; flex-direction:column; gap:3px; }
.ttt-device-name { font-size:16px; font-weight:600; color:#F8FAFC; }
.ttt-device-type { font-size:11px; color:#6366F1; text-transform:uppercase; letter-spacing:0.07em; font-weight:500; }
.ttt-mechanism-label { font-size:10px; font-weight:600; color:#64748B; text-transform:uppercase; letter-spacing:0.07em; }
.ttt-mechanism-text { font-size:13px; color:#CBD5E1; line-height:1.75; }
.ttt-exam-note { font-size:12px; color:#818CF8; background:rgba(99,102,241,0.1); border:0.5px solid rgba(99,102,241,0.25); padding:9px 12px; border-radius:8px; line-height:1.6; }

/* Test panel — light, below the teach */
.ttt-test-panel { padding:18px 22px; display:flex; flex-direction:column; gap:12px; border-top:0.5px solid #E2E8F0; }
.ttt-test-label { font-size:11px; font-weight:600; color:#6366F1; text-transform:uppercase; letter-spacing:0.07em; }
.ttt-scenario-text { font-size:13px; color:#1E293B; line-height:1.65; font-weight:500; background:#F8FAFC; border:0.5px solid #E2E8F0; padding:10px 14px; border-radius:8px; }
.ttt-question { font-size:12px; color:#475569; font-weight:500; }
.ttt-choices { display:grid; grid-template-columns:1fr 1fr; gap:8px; }
.ttt-choice-btn { background:#1E293B; color:#E2E8F0; border:1.5px solid rgba(255,255,255,0.1); border-radius:10px; padding:12px 14px; font-size:13px; font-weight:500; cursor:pointer; font-family:'DM Sans',sans-serif; text-align:center; transition:all 0.18s; line-height:1.4; }
.ttt-choice-btn:hover:not(:disabled) { background:#312E81; border-color:#6366F1; color:#fff; }
.ttt-choice-btn:disabled { opacity:0.6; cursor:default; }
.ttt-choice-btn.ttt-btn-correct { background:rgba(34,197,94,0.15) !important; border-color:#22C55E !important; color:#86EFAC !important; }
.ttt-choice-btn.ttt-btn-wrong   { background:rgba(239,68,68,0.15) !important; border-color:#EF4444 !important; color:#FCA5A5 !important; }
.ttt-feedback { font-size:13px; padding:10px 14px; border-radius:8px; line-height:1.6; }
.ttt-feedback.correct   { background:rgba(34,197,94,0.08); color:#15803D; border:0.5px solid rgba(34,197,94,0.3); }
.ttt-feedback.incorrect { background:rgba(239,68,68,0.06); color:#B91C1C; border:0.5px solid rgba(239,68,68,0.2); }

/* ---- SCENARIO DECISION CARDS (Storage, Cloud) ---- */
.scen-decision-card { background:#fff; border:1.5px solid #E2E8F0; border-radius:14px; padding:20px 22px; margin-bottom:16px; display:flex; flex-direction:column; gap:14px; transition:border-color 0.3s; }
.scen-decision-card.scen-decision-complete { border-color:#22C55E; }
.scen-decision-header { display:flex; align-items:flex-start; gap:14px; }
.scen-decision-icon { font-size:28px; flex-shrink:0; }
.scen-decision-title { font-size:15px; font-weight:600; color:#1E293B; margin-bottom:4px; }
.scen-decision-desc { font-size:13px; color:#475569; line-height:1.65; }
.scen-predict-label { font-size:11px; font-weight:600; color:#6366F1; text-transform:uppercase; letter-spacing:0.07em; }
.scen-decision-choices { display:flex; flex-wrap:wrap; gap:10px; }
.scen-choice-btn { background:#1E293B; color:#E2E8F0; border:1.5px solid rgba(255,255,255,0.12); border-radius:10px; padding:12px 18px; font-size:13px; font-weight:500; cursor:pointer; font-family:'DM Sans',sans-serif; display:flex; align-items:center; gap:8px; transition:all 0.18s; }
.scen-choice-btn:hover:not(:disabled) { background:#312E81; border-color:#6366F1; color:#fff; }
.scen-choice-btn:disabled { opacity:0.5; cursor:default; }
.scen-choice-wide { flex:1; min-width:180px; justify-content:flex-start; }
.scen-choice-icon { font-size:18px; }
.scen-choice-label { font-size:13px; font-weight:500; }
.scen-result { font-size:13px; padding:12px 14px; border-radius:10px; line-height:1.65; }
.scen-result.pass { background:rgba(34,197,94,0.08); color:#15803D; border:0.5px solid rgba(34,197,94,0.3); }
.scen-result.fail { background:rgba(239,68,68,0.06); color:#B91C1C; border:0.5px solid rgba(239,68,68,0.2); }
.scen-result.warn { background:rgba(245,158,11,0.07); color:#92400E; border:0.5px solid rgba(245,158,11,0.3); }

/* ---- VM CHAIN SLOT LAYOUT ---- */
.vm-chain-slots-row { display:flex; align-items:center; gap:6px; flex-wrap:wrap; }
.vm-slot-item { min-width:140px; }

/* ---- RESPONSIVE ---- */
@media (max-width:600px) {
  .ttt-choices { grid-template-columns:1fr; }
  .scen-decision-choices { flex-direction:column; }
  .scen-choice-btn { min-width:unset; }
}

/* ============================================
   TOPIC 4 — TEACH-FIRST REDESIGN
============================================ */

/* ---- TEACH SECTION WRAPPER ---- */
.teach-section { background:#fff; border:0.5px solid #E2E8F0; border-radius:16px; padding:22px; margin:16px 0; display:flex; flex-direction:column; gap:16px; }

/* ---- SOFTWARE STACK ---- */
.sw-stack { display:flex; flex-direction:column; gap:6px; }
.sw-layer { display:flex; align-items:center; justify-content:space-between; padding:14px 18px; border-radius:12px; border:2px solid; cursor:pointer; transition:all 0.2s; user-select:none; }
.app-layer { border-color:#6366F1; background:rgba(99,102,241,0.05); }
.os-layer  { border-color:#F59E0B; background:rgba(245,158,11,0.05); }
.fw-layer  { border-color:#22C55E; background:rgba(34,197,94,0.05); }
.hw-layer  { border-color:#EF4444; background:rgba(239,68,68,0.05); }
.sw-layer:hover { filter:brightness(0.97); transform:translateX(3px); }
.sw-layer.selected { filter:brightness(1); }
.app-layer.selected { background:rgba(99,102,241,0.12); }
.os-layer.selected  { background:rgba(245,158,11,0.12); }
.fw-layer.selected  { background:rgba(34,197,94,0.12); }
.hw-layer.selected  { background:rgba(239,68,68,0.12); }
.sw-layer.sw-layer-visited::after { content:'✓'; font-size:12px; color:#22C55E; margin-left:4px; }
.sw-layer-left { display:flex; align-items:center; gap:14px; }
.sw-layer-num { width:28px; height:28px; border-radius:50%; background:rgba(0,0,0,0.08); font-size:13px; font-weight:700; display:flex; align-items:center; justify-content:center; flex-shrink:0; color:#1E293B; }
.sw-layer-name { font-size:14px; font-weight:600; color:#1E293B; }
.sw-layer-examples { font-size:11px; color:#64748B; margin-top:2px; }
.sw-layer-arrow { font-size:20px; color:#94A3B8; transition:transform 0.2s; }

/* ---- SW DETAIL PANEL ---- */
.sw-layer-detail { background:#F8FAFC; border:0.5px solid #E2E8F0; border-radius:10px; padding:16px 18px; min-height:60px; }
.sw-layer-detail-placeholder { font-size:13px; color:#94A3B8; }
.sw-detail-header { font-size:15px; font-weight:600; color:#1E293B; margin-bottom:8px; }
.sw-detail-body { font-size:13px; color:#475569; line-height:1.75; margin:0 0 8px; }
.sw-detail-examples { font-size:12px; color:#64748B; }

/* ---- LAYER / FUNCTION PROGRESS ---- */
.sw-layer-progress { font-size:12px; color:#64748B; background:#F8FAFC; border:0.5px solid #E2E8F0; padding:8px 14px; border-radius:8px; }
.sw-layer-progress span { font-weight:600; color:#6366F1; }

/* ---- UTILITY GRID ---- */
.utility-grid { display:grid; grid-template-columns:repeat(5,1fr); gap:8px; }
.utility-card { background:#F8FAFC; border:1.5px solid #E2E8F0; border-radius:10px; padding:14px 10px; text-align:center; cursor:pointer; transition:all 0.2s; display:flex; flex-direction:column; align-items:center; gap:5px; position:relative; }
.utility-card:hover { border-color:#6366F1; background:rgba(99,102,241,0.04); }
.utility-card.active { border-color:#6366F1; background:rgba(99,102,241,0.08); }
.utility-icon { font-size:22px; }
.utility-name { font-size:11px; font-weight:500; color:#475569; line-height:1.3; }
.utility-detail-box { background:#F8FAFC; border:0.5px solid #E2E8F0; border-radius:10px; padding:14px 16px; min-height:48px; }
.osf-tick { position:absolute; top:5px; right:7px; font-size:10px; color:#22C55E; font-weight:700; }

/* ---- OS FUNCTIONS TEACH GRID ---- */
.os-functions-teach-grid { display:grid; grid-template-columns:repeat(4,1fr); gap:8px; }
.os-func-teach-card { background:#F8FAFC; border:1.5px solid #E2E8F0; border-radius:10px; padding:14px 10px; text-align:center; cursor:pointer; transition:all 0.2s; position:relative; display:flex; flex-direction:column; align-items:center; gap:5px; }
.os-func-teach-card:hover { border-color:#6366F1; background:rgba(99,102,241,0.04); }
.os-func-teach-card.active { border-color:#6366F1; background:rgba(99,102,241,0.10); }
.osf-icon { font-size:22px; }
.osf-name { font-size:11px; font-weight:500; color:#475569; line-height:1.3; }

@media (max-width:600px) {
  .utility-grid { grid-template-columns:repeat(3,1fr); }
  .os-functions-teach-grid { grid-template-columns:repeat(2,1fr); }
}

/* ============================================
   LESSON HOOKS + PHASE LABELS
============================================ */
.lesson-hook { background:linear-gradient(135deg,#0F172A 0%,#1E293B 100%); border-radius:14px; padding:20px 22px; margin:16px 0 20px; display:flex; align-items:flex-start; gap:16px; }
.hook-icon { font-size:32px; flex-shrink:0; line-height:1; }
.hook-text { font-size:14px; color:#CBD5E1; line-height:1.75; font-weight:400; }

.phase-label { font-size:12px; font-weight:600; color:#6366F1; text-transform:uppercase; letter-spacing:0.08em; margin:16px 0 10px; display:flex; align-items:center; gap:8px; }
.phase-label::after { content:''; flex:1; height:1px; background:#E2E8F0; }

.phase-controls { display:flex; gap:10px; flex-wrap:wrap; align-items:center; }

/* storage-explorer-wrap already uses existing .storage-selector/.storage-btn classes */
.storage-explorer-wrap { background:#fff; border:0.5px solid #E2E8F0; border-radius:16px; padding:20px; margin:12px 0; display:flex; flex-direction:column; gap:14px; }

/* ---- SENSOR INLINE GRID (replaces pool+drag) ---- */
.sensor-scen-prompt { font-size:12px; color:#64748B; font-weight:500; }
.sensor-inline-grid { display:flex; flex-wrap:wrap; gap:6px; margin:6px 0; }
.sensor-inline-btn { background:#F1F5F9; border:1.5px solid #E2E8F0; border-radius:8px; padding:6px 10px; font-size:12px; cursor:pointer; font-family:'DM Sans',sans-serif; color:#475569; transition:all 0.15s; white-space:nowrap; }
.sensor-inline-btn:hover:not(:disabled) { border-color:#6366F1; color:#6366F1; background:#EEF2FF; }
.sensor-inline-btn:disabled { opacity:0.5; cursor:default; }
.sensor-inline-btn.sensor-inline-active { background:#6366F1; border-color:#6366F1; color:#fff; }
.sensor-selected-row { display:flex; align-items:center; gap:10px; flex-wrap:wrap; margin-top:6px; }
.sensor-selected-slot { font-size:12px; color:#64748B; background:#F8FAFC; border:0.5px solid #E2E8F0; padding:6px 12px; border-radius:8px; min-width:100px; }

/* ---- LANG LEVEL EXPLORER (restored) ---- */
.lang-level-buttons { display:flex; gap:8px; margin-bottom:12px; flex-wrap:wrap; }
.lang-btn { background:#F1F5F9; border:1.5px solid #E2E8F0; border-radius:8px; padding:8px 18px; font-size:13px; font-weight:500; color:#64748B; cursor:pointer; font-family:'DM Sans',sans-serif; transition:all 0.2s; }
.lang-btn:hover { border-color:#6366F1; color:#6366F1; }
.lang-btn.active { background:#6366F1; border-color:#6366F1; color:#fff; }
.lang-display { background:#0F172A; border-radius:12px; padding:18px 20px; display:flex; flex-direction:column; gap:10px; }
.lang-level-header { font-size:13px; font-weight:600; }
.lang-code-block { display:flex; flex-direction:column; gap:4px; }
.lang-code-line { font-family:'DM Mono',monospace; font-size:12px; color:#86EFAC; padding:3px 8px; border-radius:4px; background:rgba(255,255,255,0.04); }
.lang-level-note { font-size:12px; color:#94A3B8; line-height:1.6; border-top:0.5px solid rgba(255,255,255,0.08); padding-top:10px; }

/* ---- CI SIM (restored original) ---- */
.ci-header { display:flex; align-items:center; gap:14px; margin-bottom:12px; flex-wrap:wrap; }
.ci-mode-switcher { display:flex; border:1.5px solid #E2E8F0; border-radius:8px; overflow:hidden; }
.ci-mode-btn { background:#F8FAFC; color:#64748B; border:none; padding:8px 18px; font-size:13px; font-weight:500; cursor:pointer; font-family:'DM Sans',sans-serif; transition:all 0.2s; }
.ci-mode-btn.active { background:#6366F1; color:#fff; }
.ci-mode-label { font-size:12px; color:#64748B; font-weight:500; }
.ci-workspace { display:grid; grid-template-columns:1fr 1fr; gap:12px; margin-bottom:12px; }
.ci-code-panel { background:#0F172A; border-radius:10px; overflow:hidden; }
.ci-output-panel { background:#0F172A; border-radius:10px; overflow:hidden; }
.ci-panel-title { font-size:11px; font-weight:600; color:#64748B; text-transform:uppercase; letter-spacing:0.07em; padding:10px 14px 0; }
.ci-code { padding:10px 14px; display:flex; flex-direction:column; gap:2px; }
.ci-output { padding:10px 14px; min-height:120px; font-size:12px; overflow-y:auto; }
.ci-line { display:flex; gap:10px; align-items:baseline; padding:3px 6px; border-radius:4px; transition:background 0.2s; }
.ci-line-num  { font-family:'DM Mono',monospace; font-size:11px; color:#475569; min-width:18px; flex-shrink:0; }
.ci-line-code { font-family:'DM Mono',monospace; font-size:12px; color:#CBD5E1; }
.ci-scanning  { background:rgba(99,102,241,0.15); }
.ci-executing { background:rgba(245,158,11,0.15); }
.ci-error     { background:rgba(239,68,68,0.15); }
.ci-error-line { font-family:'DM Mono',monospace; font-size:12px; color:#FCA5A5; padding:4px 0; }
.ci-ok-line   { font-family:'DM Mono',monospace; font-size:12px; color:#86EFAC; padding:4px 0; }
.ci-compiler-note   { font-size:12px; color:#94A3B8; margin-top:8px; line-height:1.5; }
.ci-interpreter-note{ font-size:12px; color:#94A3B8; margin-top:8px; line-height:1.5; }
@media (max-width:600px) { .ci-workspace { grid-template-columns:1fr; } }

/* ============================================
   TOPIC 6 — Automated and Emerging Technologies
============================================ */

/* ---- GREENHOUSE SYSTEM ---- */
.gh-system-layout { display:grid; grid-template-columns:1fr 30px 160px 30px 1fr; gap:0; align-items:start; background:#fff; border:0.5px solid #E2E8F0; border-radius:16px; padding:20px; margin:12px 0; }
.gh-col { display:flex; flex-direction:column; gap:8px; }
.gh-col-center { align-items:center; }
.gh-col-label { font-size:10px; font-weight:600; color:#94A3B8; text-transform:uppercase; letter-spacing:0.08em; margin-bottom:4px; }
.gh-wire-col { display:flex; align-items:center; justify-content:center; padding-top:40px; }
.gh-wire-line { width:100%; height:2px; background:#E2E8F0; }
.gh-component { background:#F8FAFC; border:1.5px solid #E2E8F0; border-radius:10px; padding:10px 12px; cursor:pointer; transition:all 0.2s; display:flex; flex-direction:column; gap:4px; }
.gh-component:hover { border-color:#6366F1; background:#EEF2FF; }
.gh-comp-icon { font-size:18px; }
.gh-comp-label { font-size:12px; font-weight:500; color:#1E293B; }
.gh-comp-status { font-size:10px; color:#94A3B8; }
.gh-comp-connected { border-color:#22C55E; background:rgba(34,197,94,0.06); }
.gh-comp-connected .gh-comp-status { color:#15803D; }
.gh-comp-failed { border-color:#EF4444; background:rgba(239,68,68,0.08); animation:pulse-red 1s infinite; }
.gh-actuator-firing { border-color:#F59E0B; background:rgba(245,158,11,0.1); transform:scale(1.04); }
@keyframes pulse-red { 0%,100%{box-shadow:0 0 0 0 rgba(239,68,68,0.4)} 50%{box-shadow:0 0 0 6px rgba(239,68,68,0)} }
.gh-microprocessor { background:#0F172A; border-radius:12px; padding:16px; text-align:center; display:flex; flex-direction:column; gap:8px; width:100%; box-sizing:border-box; }
.gh-cpu-icon { font-size:28px; }
.gh-cpu-label { font-size:12px; font-weight:600; color:#E2E8F0; }
.gh-cpu-activity { font-size:11px; color:#64748B; line-height:1.4; }
.gh-cpu-active { border:1.5px solid #6366F1; box-shadow:0 0 0 3px rgba(99,102,241,0.2); }
.gh-cpu-pulse { animation:pulse-indigo 0.6s ease; }
@keyframes pulse-indigo { 0%,100%{box-shadow:0 0 0 0 rgba(99,102,241,0.5)} 50%{box-shadow:0 0 0 10px rgba(99,102,241,0)} }
.gh-visual { display:flex; align-items:center; justify-content:space-between; background:#F0FDF4; border:0.5px solid #BBF7D0; border-radius:12px; padding:16px 20px; margin:12px 0; }
.gh-plant { font-size:48px; transition:all 0.5s; }
.gh-readings { display:flex; gap:20px; flex-wrap:wrap; }
.gh-reading { display:flex; flex-direction:column; gap:2px; }
.gh-r-label { font-size:10px; color:#64748B; }
.gh-r-val { font-size:14px; font-weight:600; color:#1E293B; font-family:'DM Mono',monospace; }
.gh-log { background:#0F172A; border-radius:10px; padding:12px 14px; max-height:160px; display:flex; flex-direction:column; gap:6px; }
.gh-log-label { font-size:10px; color:#475569; text-transform:uppercase; letter-spacing:0.07em; font-weight:600; }
.gh-log-entries { overflow-y:auto; display:flex; flex-direction:column; gap:4px; flex:1; }
.gh-log-entry { font-size:12px; font-family:'DM Mono',monospace; padding:3px 0; }
.gh-log-info    { color:#64748B; }
.gh-log-success { color:#86EFAC; }
.gh-log-warn    { color:#FCD34D; }
.gh-log-error   { color:#FCA5A5; }

/* ---- FACTORY SCENARIO ---- */
.factory-scen-header { display:flex; align-items:center; gap:14px; margin-bottom:12px; }
.factory-scen-num { font-size:11px; color:#94A3B8; font-weight:500; text-transform:uppercase; letter-spacing:0.07em; }
.factory-scen-title { font-size:16px; font-weight:600; color:#1E293B; }
.factory-scen-story { font-size:14px; color:#475569; line-height:1.7; background:#F8FAFC; border:0.5px solid #E2E8F0; border-radius:10px; padding:14px 16px; margin-bottom:16px; }
.factory-scen-decision { font-size:13px; font-weight:600; color:#1E293B; margin-bottom:10px; }
.factory-scen-options { display:flex; gap:12px; flex-wrap:wrap; margin-bottom:16px; }
.factory-choice-btn { padding:14px 24px; border-radius:12px; font-size:14px; font-weight:600; cursor:pointer; font-family:'DM Sans',sans-serif; border:2px solid; transition:all 0.2s; }
.factory-choice-yes { background:#1E293B; color:#E2E8F0; border-color:rgba(255,255,255,0.15); }
.factory-choice-yes:hover { background:#312E81; border-color:#6366F1; color:#fff; }
.factory-choice-no  { background:#fff; color:#1E293B; border-color:#E2E8F0; }
.factory-choice-no:hover  { border-color:#EF4444; color:#DC2626; }
.factory-consequence-log { display:flex; flex-direction:column; gap:8px; background:#0F172A; border-radius:12px; padding:16px; max-height:280px; overflow-y:auto; }
.factory-log-entry { font-size:13px; padding:8px 12px; border-radius:8px; line-height:1.5; animation:fadeSlideIn 0.3s ease; }
@keyframes fadeSlideIn { from{opacity:0;transform:translateY(6px)} to{opacity:1;transform:translateY(0)} }
.factory-log-good   { background:rgba(34,197,94,0.1); color:#86EFAC; }
.factory-log-bad    { background:rgba(239,68,68,0.1); color:#FCA5A5; }
.factory-log-reveal { background:rgba(245,158,11,0.15); color:#FCD34D; font-weight:600; font-size:14px; padding:12px 14px; }
.factory-next-wrap  { margin-top:12px; }
.factory-summary { background:#fff; border:0.5px solid #E2E8F0; border-radius:14px; padding:20px; display:flex; flex-direction:column; gap:16px; }
.factory-summary-title { font-size:16px; font-weight:600; color:#1E293B; }
.factory-summary-grid { display:grid; grid-template-columns:1fr 1fr; gap:12px; }
.factory-summary-col { border-radius:10px; padding:14px; display:flex; flex-direction:column; gap:8px; }
.factory-summary-good { background:rgba(34,197,94,0.06); border:0.5px solid rgba(34,197,94,0.3); }
.factory-summary-bad  { background:rgba(239,68,68,0.05); border:0.5px solid rgba(239,68,68,0.2); }
.factory-summary-label { font-size:12px; font-weight:600; text-transform:uppercase; letter-spacing:0.07em; margin-bottom:4px; }
.factory-summary-good .factory-summary-label { color:#15803D; }
.factory-summary-bad  .factory-summary-label { color:#DC2626; }
.factory-summary-item { font-size:13px; color:#475569; padding:6px 0; border-bottom:0.5px solid rgba(0,0,0,0.06); line-height:1.5; }
.factory-summary-item:last-child { border-bottom:none; }

/* ---- ROBOT SORT ---- */
.robot-sort-grid { display:grid; grid-template-columns:1fr 1fr; gap:12px; margin:12px 0; }
.robot-sort-card { background:#fff; border:1.5px solid #E2E8F0; border-radius:12px; padding:14px; display:flex; flex-direction:column; gap:10px; transition:border-color 0.3s; }
.rscard-correct { border-color:#22C55E; }
.rscard-wrong   { border-color:#EF4444; }
.robot-sort-label { font-size:14px; font-weight:500; color:#1E293B; }
.robot-sort-btns { display:flex; gap:8px; }
.robot-sort-btn { flex:1; padding:9px 12px; border-radius:8px; font-size:13px; font-weight:500; cursor:pointer; font-family:'DM Sans',sans-serif; border:1.5px solid; transition:all 0.18s; }
.robot-sort-yes { background:#1E293B; color:#E2E8F0; border-color:rgba(255,255,255,0.1); }
.robot-sort-yes:hover:not(:disabled) { background:#312E81; border-color:#6366F1; }
.robot-sort-no  { background:#fff; color:#1E293B; border-color:#E2E8F0; }
.robot-sort-no:hover:not(:disabled)  { border-color:#EF4444; color:#DC2626; }
.robot-sort-btn:disabled { opacity:0.5; cursor:default; }
.robot-sort-result { font-size:13px; padding:10px 12px; border-radius:8px; line-height:1.6; }
.robot-sort-result-correct { background:rgba(34,197,94,0.07); color:#15803D; border:0.5px solid rgba(34,197,94,0.3); }
.robot-sort-result-wrong   { background:rgba(239,68,68,0.06); color:#B91C1C; border:0.5px solid rgba(239,68,68,0.2); }

/* ---- MARS COLONY ---- */
.mars-layout { display:grid; grid-template-columns:240px 1fr; gap:16px; }
.mars-panel-label { font-size:11px; font-weight:600; color:#94A3B8; text-transform:uppercase; letter-spacing:0.07em; margin-bottom:10px; }
.mars-robots-pool { display:flex; flex-direction:column; gap:8px; }
.mars-robot-chip { background:#0F172A; border:1.5px solid rgba(255,255,255,0.1); border-radius:10px; padding:10px 14px; cursor:grab; display:flex; align-items:center; gap:10px; transition:all 0.18s; user-select:none; }
.mars-robot-chip:hover { border-color:#6366F1; }
.mars-chip-selected { border-color:#6366F1; background:#312E81; box-shadow:0 0 0 3px rgba(99,102,241,0.25); }
.mars-chip-deployed { opacity:0.4; cursor:default; }
.mars-robot-icon { font-size:20px; flex-shrink:0; }
.mars-robot-label { font-size:12px; color:#E2E8F0; font-weight:500; }
.mars-roles-panel { display:flex; flex-direction:column; gap:8px; }
.mars-role-card { background:#fff; border:1.5px solid #E2E8F0; border-radius:12px; padding:14px; display:flex; flex-direction:column; gap:8px; transition:border-color 0.3s; }
.mars-role-success { border-color:#22C55E; background:rgba(34,197,94,0.02); }
.mars-role-fail    { border-color:#EF4444; background:rgba(239,68,68,0.02); }
.mars-role-header { display:flex; align-items:center; justify-content:space-between; }
.mars-role-label { font-size:14px; font-weight:600; color:#1E293B; }
.mars-role-submit { font-size:12px; padding:6px 14px; }
.mars-role-drop { border:1.5px dashed #CBD5E1; border-radius:8px; padding:10px 14px; font-size:13px; color:#94A3B8; cursor:pointer; min-height:44px; display:flex; align-items:center; transition:all 0.2s; }
.mars-role-drop:hover { border-color:#6366F1; background:#EEF2FF; }
.mars-drop-filled { border-style:solid; border-color:#6366F1; color:#1E293B; background:#EEF2FF; }
.mars-role-result { font-size:13px; padding:10px 12px; border-radius:8px; line-height:1.6; animation:fadeSlideIn 0.3s ease; }
.mars-result-success { background:rgba(34,197,94,0.08); color:#15803D; border:0.5px solid rgba(34,197,94,0.3); }
.mars-result-fail    { background:rgba(239,68,68,0.06); color:#B91C1C; border:0.5px solid rgba(239,68,68,0.2); }

/* ---- AI TRAINER ---- */
.ai-trainer-layout { display:grid; grid-template-columns:1fr 260px; gap:16px; }
.ai-trainer-emails { display:flex; flex-direction:column; gap:10px; max-height:480px; overflow-y:auto; padding-right:4px; }
.ai-email-card { background:#fff; border:1.5px solid #E2E8F0; border-radius:12px; padding:14px; display:flex; flex-direction:column; gap:8px; transition:border-color 0.3s; }
.ai-card-correct { border-color:#22C55E; }
.ai-card-wrong   { border-color:#EF4444; }
.ai-email-header { display:flex; flex-direction:column; gap:2px; }
.ai-email-subject { font-size:13px; font-weight:600; color:#1E293B; }
.ai-email-sender  { font-size:11px; color:#94A3B8; font-family:'DM Mono',monospace; }
.ai-email-preview { font-size:12px; color:#475569; line-height:1.5; border-left:2px solid #E2E8F0; padding-left:10px; }
.ai-email-label-row { display:flex; gap:8px; }
.ai-label-btn { flex:1; padding:8px 12px; border-radius:8px; font-size:12px; font-weight:500; cursor:pointer; font-family:'DM Sans',sans-serif; border:1.5px solid; transition:all 0.18s; }
.ai-label-spam    { background:#1E293B; color:#FCA5A5; border-color:rgba(239,68,68,0.3); }
.ai-label-spam:hover:not(:disabled) { background:rgba(239,68,68,0.15); border-color:#EF4444; color:#DC2626; }
.ai-label-notspam { background:#fff; color:#15803D; border-color:rgba(34,197,94,0.3); }
.ai-label-notspam:hover:not(:disabled) { background:rgba(34,197,94,0.06); border-color:#22C55E; }
.ai-label-btn:disabled { opacity:0.5; cursor:default; }
.ai-email-labelled { font-size:12px; padding:6px 10px; border-radius:6px; }
.ai-labelled-correct { background:rgba(34,197,94,0.07); color:#15803D; }
.ai-labelled-wrong   { background:rgba(239,68,68,0.06); color:#B91C1C; }
.ai-trainer-panel { background:#F8FAFC; border:0.5px solid #E2E8F0; border-radius:12px; padding:14px; display:flex; flex-direction:column; gap:12px; position:sticky; top:12px; }
.ai-trainer-panel-title { font-size:12px; font-weight:600; color:#1E293B; }
.ai-rules-list { display:flex; flex-direction:column; gap:8px; flex:1; }
.ai-rule-placeholder { font-size:12px; color:#94A3B8; }
.ai-rule-item { display:flex; align-items:center; gap:8px; }
.ai-rule-feature { font-size:11px; color:#475569; min-width:110px; flex-shrink:0; }
.ai-rule-bar-wrap { flex:1; height:6px; background:#E2E8F0; border-radius:3px; overflow:hidden; }
.ai-rule-bar { height:100%; border-radius:3px; transition:width 0.4s,background 0.4s; }
.ai-rule-pct { font-size:10px; color:#64748B; font-family:'DM Mono',monospace; white-space:nowrap; }
.ai-train-progress { display:flex; flex-direction:column; gap:4px; }
.ai-train-progress-label { font-size:11px; color:#64748B; }
.ai-train-bar-track { height:4px; background:#E2E8F0; border-radius:2px; overflow:hidden; }
.ai-train-bar { height:100%; background:#6366F1; border-radius:2px; transition:width 0.3s; }

/* AI test layout */
.ai-test-layout { display:flex; flex-direction:column; gap:14px; }
.ai-test-intro { background:#F8FAFC; border:0.5px solid #E2E8F0; border-radius:10px; padding:14px; }
.ai-test-title { font-size:14px; font-weight:600; color:#1E293B; margin-bottom:4px; }
.ai-test-desc  { font-size:13px; color:#64748B; }
.ai-test-predict-row { display:flex; align-items:center; gap:10px; }
.ai-test-label { font-size:12px; color:#64748B; }
.ai-test-prediction { font-size:13px; }
.ai-test-reason { font-size:12px; color:#64748B; line-height:1.5; border-top:0.5px solid #F1F5F9; padding-top:6px; margin-top:4px; }
.ai-test-reveal { background:rgba(99,102,241,0.06); border:0.5px solid rgba(99,102,241,0.25); border-radius:10px; padding:14px 16px; }
.ai-test-reveal-title { font-size:13px; font-weight:600; color:#6366F1; margin-bottom:6px; }
.ai-test-reveal-body  { font-size:13px; color:#475569; line-height:1.65; }

/* ---- ML TRAINER (bad data challenge) ---- */
.ml-trainer-wrap { display:flex; flex-direction:column; gap:12px; }
.ml-challenge-label { font-size:13px; font-weight:500; color:#6366F1; background:rgba(99,102,241,0.06); border:0.5px solid rgba(99,102,241,0.25); padding:10px 14px; border-radius:8px; }
.ml-trainer-emails { display:flex; flex-direction:column; gap:10px; max-height:400px; overflow-y:auto; }
.ml-model-panel { background:#F8FAFC; border:0.5px solid #E2E8F0; border-radius:12px; padding:14px; display:flex; flex-direction:column; gap:10px; }
.ml-model-title  { font-size:12px; font-weight:600; color:#1E293B; }
.ml-model-status { font-size:13px; color:#64748B; }
.ml-bad-count    { font-size:12px; color:#DC2626; background:rgba(239,68,68,0.06); padding:8px 12px; border-radius:8px; }
.ml-test-wrap    { display:flex; flex-direction:column; gap:12px; }
.ml-test-title   { font-size:14px; font-weight:600; color:#1E293B; }
.ml-test-emails  { display:flex; flex-direction:column; gap:10px; }
.ml-test-result  { font-size:13px; padding:8px 12px; border-radius:8px; animation:fadeSlideIn 0.3s ease; }
.ml-result-correct { background:rgba(34,197,94,0.07); color:#15803D; border:0.5px solid rgba(34,197,94,0.3); }
.ml-result-wrong   { background:rgba(239,68,68,0.06); color:#B91C1C; border:0.5px solid rgba(239,68,68,0.2); }
.ml-conclusion { padding:14px 16px; border-radius:10px; font-size:13px; line-height:1.65; }
.ml-conclusion-bad { background:rgba(239,68,68,0.06); color:#B91C1C; border:0.5px solid rgba(239,68,68,0.25); }
.ml-conclusion-ok  { background:rgba(34,197,94,0.07); color:#15803D; border:0.5px solid rgba(34,197,94,0.3); }

/* ---- EXPERT SYSTEM ---- */
.expert-interface { background:#fff; border:0.5px solid #E2E8F0; border-radius:14px; overflow:hidden; }
.expert-interface-label { font-size:10px; font-weight:600; color:#6366F1; text-transform:uppercase; letter-spacing:0.08em; background:rgba(99,102,241,0.06); padding:10px 16px; border-bottom:0.5px solid #E2E8F0; }
.expert-patient-info { font-size:13px; color:#475569; padding:12px 16px 0; }
.expert-patient-info strong { color:#1E293B; }
.expert-questions { padding:12px 16px; display:flex; flex-direction:column; gap:8px; }
.expert-question { display:flex; align-items:center; justify-content:space-between; padding:8px 12px; background:#F8FAFC; border-radius:8px; border:0.5px solid #E2E8F0; transition:all 0.2s; }
.expert-q-yes { background:rgba(34,197,94,0.06); border-color:rgba(34,197,94,0.3); }
.expert-q-no  { background:#F8FAFC; }
.expert-question-text { font-size:13px; color:#1E293B; font-weight:500; }
.expert-question-btns { display:flex; gap:6px; flex-shrink:0; }
.expert-yn-btn { padding:5px 14px; border-radius:6px; font-size:12px; font-weight:500; cursor:pointer; font-family:'DM Sans',sans-serif; border:1.5px solid; transition:all 0.15s; }
.expert-yes { background:#1E293B; color:#86EFAC; border-color:rgba(34,197,94,0.3); }
.expert-yes:hover:not(:disabled) { background:rgba(34,197,94,0.15); border-color:#22C55E; color:#15803D; }
.expert-no  { background:#fff; color:#94A3B8; border-color:#E2E8F0; }
.expert-no:hover:not(:disabled)  { border-color:#EF4444; color:#DC2626; }
.expert-yn-btn:disabled { opacity:0.5; cursor:default; }
.expert-engine-log { background:#0F172A; margin:0 16px 16px; border-radius:10px; padding:12px 14px; max-height:140px; overflow-y:auto; }
.expert-engine-label { font-size:10px; color:#475569; text-transform:uppercase; letter-spacing:0.07em; font-weight:600; margin-bottom:8px; }
.expert-engine-entries { display:flex; flex-direction:column; gap:4px; }
.expert-engine-entry { font-size:11px; font-family:'DM Mono',monospace; color:#64748B; }
.expert-engine-match   { color:#86EFAC; }
.expert-engine-partial { color:#FCD34D; }
.expert-diagnosis { margin:0 16px 16px; padding:14px 16px; border-radius:10px; }
.expert-diagnosis-found { background:rgba(34,197,94,0.08); border:0.5px solid rgba(34,197,94,0.3); }
.expert-diagnosis-unknown { background:rgba(245,158,11,0.08); border:0.5px solid rgba(245,158,11,0.3); }
.expert-diagnosis-label { font-size:10px; color:#64748B; text-transform:uppercase; letter-spacing:0.07em; font-weight:600; margin-bottom:6px; }
.expert-diagnosis-result { font-size:18px; font-weight:600; color:#1E293B; }
.expert-diagnosis-confidence { font-size:12px; color:#6366F1; margin-top:4px; }
.expert-diagnosis-note { font-size:12px; color:#64748B; margin-top:6px; }
.engineer-section { background:#fff; border:0.5px solid #E2E8F0; border-radius:14px; padding:20px; display:flex; flex-direction:column; gap:14px; margin-top:16px; }
.engineer-title { font-size:15px; font-weight:600; color:#1E293B; }
.engineer-desc { font-size:13px; color:#475569; line-height:1.65; }
.engineer-rule-builder { display:flex; flex-direction:column; gap:10px; }
.engineer-rule-label { font-size:11px; font-weight:600; color:#6366F1; text-transform:uppercase; letter-spacing:0.07em; }
.engineer-checkboxes { display:flex; flex-wrap:wrap; gap:8px; padding:10px; background:#F8FAFC; border:0.5px solid #E2E8F0; border-radius:8px; }
.engineer-check-label { display:flex; align-items:center; gap:6px; font-size:12px; color:#475569; cursor:pointer; padding:4px 8px; border-radius:6px; transition:background 0.15s; }
.engineer-check-label:hover { background:#EEF2FF; color:#6366F1; }
.engineer-then-input { padding:8px 12px; border:1.5px solid #E2E8F0; border-radius:8px; font-size:13px; font-family:'DM Sans',sans-serif; outline:none; width:100%; box-sizing:border-box; }
.engineer-then-input:focus { border-color:#6366F1; }
.engineer-conf-input { padding:8px 12px; border:1.5px solid #E2E8F0; border-radius:8px; font-size:13px; font-family:'DM Mono',monospace; outline:none; width:80px; }
.engineer-rule-preview { font-size:13px; color:#15803D; background:rgba(34,197,94,0.07); padding:12px 14px; border-radius:8px; border:0.5px solid rgba(34,197,94,0.3); line-height:1.6; }
.engineer-rule-preview code { font-family:'DM Mono',monospace; font-size:12px; }
.expert-component-labels { display:grid; grid-template-columns:1fr 1fr; gap:10px; margin-top:8px; }
.expert-comp-card { background:#fff; border:0.5px solid #E2E8F0; border-radius:10px; padding:14px; display:flex; flex-direction:column; gap:6px; }
.expert-comp-name { font-size:13px; font-weight:600; color:#6366F1; }
.expert-comp-desc { font-size:12px; color:#475569; line-height:1.55; }

/* ---- RESPONSIVE ---- */
@media (max-width:680px) {
  .gh-system-layout { grid-template-columns:1fr 16px 120px 16px 1fr; }
  .mars-layout { grid-template-columns:1fr; }
  .ai-trainer-layout { grid-template-columns:1fr; }
  .robot-sort-grid { grid-template-columns:1fr; }
  .factory-summary-grid { grid-template-columns:1fr; }
  .expert-component-labels { grid-template-columns:1fr; }
}


/* ---- Lumira brand emblem ---- */
.brandmark{width:30px;height:32px;display:block;flex-shrink:0;}
.brandmark.small{width:24px;height:26px;}