/* Additive presentation layer; existing lesson styles and scientific colours remain. */
:root{--chem-control-accent:#6366f1}body,button,input,select,textarea{font-family:'DM Sans',system-ui,sans-serif}h1,h2,.topic-heading h1{font-family:'Fraunces',Georgia,serif}.lesson-tabs button[aria-current="step"],.lesson-tabs button.active{color:var(--chem-control-accent);border-color:var(--chem-control-accent)}.completion-primary,.lesson-nav button:not(:first-child),.ct-cta{background:var(--chem-control-accent)}input[type=range]{accent-color:var(--chem-control-accent)}.chem-progress-panel{background:#fff;border:1px solid #e2e8f0;padding:24px;border-radius:12px;margin:24px 0;color:#475569}.chem-progress-panel p{line-height:1.6}.chem-completion-badge{display:block;font-size:13px;color:#6366f1;margin-top:10px}.chem-availability-corrected .topic-subtopics{display:none}.completion-note+button{padding:10px 16px;border-radius:8px;border:1px solid #cbd5e1;background:white;color:#475569}
.subtopic-complete h2{font-family:'Fraunces',Georgia,serif}a,summary{color:#6366f1}.completion-primary,header a{color:white}