:root{--brand:#183044;--brand-2:#FDC62B;--brand-3:#6FC4C1;--brand-2-tint:#FFF4D5;--brand-3-tint:#E2F3F3;--brand-2-line:#F6D780;--brand-3-line:#B7E1E0;--navy:#183044;--navy2:#183044;--coral:#FDC62B;--berry:#183044;--blush:#FFF4D5;--surface:#fff;--text:#183044;--muted:#52646b;--line:#d8e1e4;--focus:#183044;--shadow:0 18px 60px rgba(24,48,68,.13);font-family:"Aptos","Segoe UI",system-ui,sans-serif;color:var(--text);background:#edf3f4;font-size:16px}
*{box-sizing:border-box}body{margin:0;min-height:100vh;background:radial-gradient(circle at 10% 5%,#fff 0,#f6fafb 35%,#edf3f4 100%);line-height:1.5}.skip-link{position:fixed;left:1rem;top:-4rem;background:#fff;color:var(--navy);padding:.8rem 1rem;z-index:20}.skip-link:focus{top:1rem}.course-shell{width:min(1280px,calc(100% - 2rem));min-height:min(860px,calc(100vh - 2rem));margin:1rem auto;background:var(--surface);border-radius:24px;box-shadow:var(--shadow);overflow:hidden;display:grid;grid-template-rows:auto auto 1fr auto}.topbar{min-height:76px;padding:1rem 1.5rem;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line)}.brand{display:flex;align-items:center;gap:.75rem;color:var(--navy)}.brand-mark{width:42px;height:42px;border-radius:13px;background:var(--brand-2);display:grid;place-items:center;font-size:1.2rem}.brand span:last-child{display:grid}.brand small{color:var(--muted);font-size:.8rem}.top-actions{display:flex;gap:.5rem}.icon-button,.quiet-button{border:1px solid var(--line);background:#fff;color:var(--navy);border-radius:10px;padding:.65rem .85rem;font-weight:700}.stage{min-height:610px;padding:clamp(1.5rem,4vw,4rem);display:grid;grid-template-columns:minmax(0,1fr) minmax(260px,340px);gap:clamp(2rem,5vw,5rem);align-items:center;background:linear-gradient(135deg,#fff 0 70%,var(--blush) 70%)}.lesson{max-width:780px}.eyebrow{color:var(--brand);font-size:.85rem;font-weight:800;letter-spacing:.08em;text-transform:uppercase;margin:0 0 .75rem}.lesson h1{font-size:clamp(2.2rem,5vw,4.8rem);line-height:1.02;color:var(--navy);letter-spacing:-.04em;margin:.2rem 0 1.2rem}.lesson h2{font-size:clamp(1.8rem,3.3vw,3.2rem);line-height:1.08;color:var(--navy);letter-spacing:-.03em;margin:.2rem 0 1rem}.lead{font-size:clamp(1.08rem,1.6vw,1.35rem);max-width:64ch;color:#183044}.pill{display:inline-flex;padding:.45rem .7rem;border-radius:999px;background:var(--blush);color:var(--brand);font-weight:800}.presenter{align-self:stretch;display:flex;flex-direction:column;justify-content:center;max-width:340px}.presenter.is-hidden{visibility:hidden}.video-frame{position:relative;border-radius:24px;overflow:hidden;background:var(--blush);aspect-ratio:3/4;box-shadow:0 12px 35px rgba(24,48,68,0.18)}.video-frame video{width:100%;height:100%;object-fit:cover;display:block}.ai-label{position:absolute;left:.65rem;bottom:.65rem;background:rgba(24,48,68,0.9);color:white;border-radius:999px;padding:.35rem .6rem;font-size:.75rem}.narration-controls{display:flex;gap:.5rem;margin-top:.8rem}.audio-button{border:0;background:var(--brand-2);color:#fff;border-radius:12px;padding:.75rem 1rem;font-weight:800;flex:1}.captions{min-height:3.8rem;background:#fff;border:1px solid var(--line);border-radius:12px;padding:.65rem .8rem;margin:.65rem 0 0;font-size:.88rem}.captions:empty{display:none}.transcript{margin-top:.5rem;color:var(--muted);font-size:.88rem}.transcript summary{cursor:pointer;font-weight:700;color:var(--navy)}.transcript p{margin:.5rem 0}.cards{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:1rem;margin-top:1.5rem}.cards.three{grid-template-columns:repeat(3,minmax(0,1fr))}.card{border:1px solid var(--line);border-radius:18px;padding:1.2rem;background:#fff;text-align:left;color:var(--text);min-height:130px;box-shadow:0 4px 18px rgba(24,48,68,0.06)}button.card{cursor:pointer;font:inherit}.card:hover,.card:focus-visible{border-color:var(--focus);transform:translateY(-2px)}.card.active,.card.visited{border:2px solid var(--brand-2);background:var(--blush)}.card h3{color:var(--navy);margin:.1rem 0 .5rem;font-size:1.15rem}.card p{margin:0;color:var(--muted)}.icon{display:grid;place-items:center;width:44px;height:44px;border-radius:13px;background:var(--blush);font-size:1.25rem;margin-bottom:.7rem}.objective-list{display:grid;gap:.7rem;padding:0;list-style:none;margin:1.4rem 0}.objective-list li{display:flex;gap:.8rem;padding:.8rem 1rem;border-left:4px solid var(--brand-2);background:#f7fafb;border-radius:0 12px 12px 0}.objective-list b{color:var(--brand)}.module-map{display:grid;gap:.8rem;margin-top:1.5rem}.module-row{display:grid;grid-template-columns:44px 1fr auto;align-items:center;gap:1rem;padding:1rem;border-radius:16px;border:1px solid var(--line)}.module-row.active{border:2px solid var(--brand-2);background:var(--blush)}.module-row.disabled{opacity:.58}.module-number{width:42px;height:42px;border-radius:50%;display:grid;place-items:center;background:var(--navy);color:#fff;font-weight:800}.explore-status{font-size:.9rem;color:var(--brand);font-weight:800;margin-top:1rem}.definition-panel{margin-top:1rem;border-radius:18px;background:var(--navy);color:#fff;padding:1.3rem;min-height:108px}.definition-panel h3{margin:0 0 .4rem}.definition-panel p{margin:0}.check{margin-top:1.2rem;padding:1rem;border-radius:16px;background:#f5f8f9}.check legend{font-weight:800;color:var(--navy);padding:0 .25rem}.answer-row{display:flex;gap:.6rem;flex-wrap:wrap}.answer-row button{background:#fff;border:1px solid var(--line);border-radius:10px;padding:.65rem .9rem}.feedback{font-weight:700;margin:.7rem 0 0;color:var(--brand)}.course-footer{display:flex;align-items:center;gap:2rem;justify-content:space-between;padding:1rem 1.5rem;border-top:1px solid var(--line);background:#fff}.progress-wrap{display:flex;align-items:center;gap:1rem;flex:1;color:var(--muted);font-size:.9rem}.progress-track{height:8px;background:#e5ecee;border-radius:999px;overflow:hidden;max-width:360px;flex:1}.progress-track span{display:block;height:100%;width:11%;background:var(--brand-2);border-radius:inherit;transition:width .3s}.pager{display:flex;gap:.7rem}.primary-button,.secondary-button{min-height:46px;border-radius:12px;padding:.7rem 1.05rem;font-weight:800;border:1px solid var(--navy)}.primary-button{background:var(--brand-2);color:#fff;border-color:var(--brand-2)}.secondary-button{background:#fff;color:var(--navy)}button:disabled{opacity:.45;cursor:not-allowed}button:focus-visible,summary:focus-visible,input:focus-visible{outline:3px solid var(--focus);outline-offset:3px}.toast{position:fixed;left:50%;bottom:5.5rem;transform:translateX(-50%) translateY(20px);background:var(--navy);color:#fff;padding:.8rem 1rem;border-radius:12px;opacity:0;pointer-events:none;transition:.2s}.toast.show{opacity:1;transform:translateX(-50%) translateY(0)}@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
@media(max-width:800px){.course-shell{width:100%;margin:0;border-radius:0;min-height:100vh}.topbar{padding:.8rem 1rem}.brand small{display:none}.icon-button{font-size:0}.icon-button::first-letter{font-size:1rem}.stage{grid-template-columns:1fr;background:#fff;padding:1.5rem;align-items:start}.presenter{max-width:none;display:grid;grid-template-columns:120px 1fr;gap:1rem;align-items:start}.video-frame{grid-row:1/4}.narration-controls{margin:0}.cards,.cards.three{grid-template-columns:1fr}.course-footer{align-items:stretch;flex-direction:column;gap:.8rem}.progress-wrap{width:100%}.pager{justify-content:space-between}.module-row{grid-template-columns:44px 1fr}.module-row .status{grid-column:2}}@media(max-width:480px){.presenter{grid-template-columns:88px 1fr}.top-actions{gap:.25rem}.course-footer{padding:.8rem}.pager button{flex:1}}