*{box-sizing:border-box}:root{font-family:Segoe UI,Arial,sans-serif;color:#edf3f8;background:#0b0f14;--blue:#47cdf5;--gold:#ffb400;--muted:#a8b8c7;--line:#2a3744}body{margin:0}a{color:inherit}button,input{font:inherit}button{cursor:pointer}button:disabled{cursor:default;opacity:.55}button:focus-visible,a:focus-visible,input:focus-visible{outline:3px solid var(--gold);outline-offset:4px}.skip{position:fixed;top:-80px;left:20px;background:var(--gold);color:#111;padding:14px;z-index:5}.skip:focus{top:10px}.shell{display:grid;grid-template-columns:242px minmax(0,1fr);min-height:100vh}.sidebar{padding:32px 22px;background:#111820;border-right:1px solid var(--line);position:sticky;top:0;height:100vh;display:flex;flex-direction:column}.brand{display:flex;align-items:center;gap:10px;text-decoration:none;font-size:21px;font-weight:750}.brand img{width:46px;height:46px;object-fit:contain}.brand small{display:block;font-size:9px;letter-spacing:3px;color:var(--muted);margin-top:4px}.workspace-label{font-size:10px;letter-spacing:2px;color:var(--muted);margin:55px 10px 16px}nav{display:grid;gap:8px}nav a{display:flex;gap:13px;align-items:center;text-decoration:none;padding:14px 12px;border-radius:9px;color:var(--muted);font-size:14px}nav a.active{background:#123340;color:var(--blue);box-shadow:inset 3px 0 var(--blue)}nav a:hover{background:#1d2a35;color:white}.sidebar-foot{margin-top:auto;padding:30px 10px 0}.spark{color:var(--gold);font-size:30px;display:block;margin-bottom:15px}.sidebar-foot strong{font-size:18px}.sidebar-foot p{font-size:13px;line-height:1.7;color:var(--muted)}.tag{font-size:9px;letter-spacing:1.2px;color:var(--muted)}.page{min-width:0}header{height:80px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 40px;font-size:13px;color:var(--muted)}header strong{color:#edf3f8}.preview-pill,.badge{border:1px solid #365364;border-radius:20px;padding:6px 10px;font-size:11px;color:#abdded}main{max-width:1420px;margin:auto;padding:38px 40px 60px;outline:none}footer{padding:18px 40px;border-top:1px solid var(--line);font-size:12px;line-height:1.7;color:var(--muted)}.eyebrow{color:var(--blue);font-size:11px;letter-spacing:2px;font-weight:700;margin:0 0 12px}h1{font-size:clamp(29px,3.3vw,46px);letter-spacing:-1.2px;line-height:1.12;margin:0 0 18px}h2{font-size:22px;letter-spacing:-.4px}h3{font-size:17px}.intro{color:var(--muted);line-height:1.7;max-width:650px}.hero{position:relative;overflow:hidden;border:1px solid #295367;background:linear-gradient(110deg,#142b38,#14212b);border-radius:16px;padding:32px;margin:26px 0 30px}.hero:after{content:'01';position:absolute;right:25px;bottom:-40px;font-size:220px;line-height:1;font-weight:800;color:#ffffff06;pointer-events:none}.hero h2{font-size:30px;margin:18px 0 10px}.hero p{color:#b9cbd7;max-width:550px;line-height:1.7}.row{display:flex;gap:12px;align-items:center;flex-wrap:wrap}.primary,.secondary{border-radius:8px;padding:12px 18px;font-weight:650;border:1px solid var(--line);text-decoration:none;display:inline-block;font-size:13px}.primary{background:var(--blue);color:#07161d;border-color:var(--blue)}.secondary{background:#1a2732;color:#eef5fa}.primary:hover{background:#93e5ff}.secondary:hover{background:#2a3c4b}.section-top{display:flex;align-items:center;justify-content:space-between;gap:15px;margin:30px 0 16px}.section-top h2{margin:0}.muted{color:var(--muted);font-size:13px;line-height:1.7}.cards{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.card{border:1px solid var(--line);background:#141d26;border-radius:12px;padding:22px;min-width:0}.card h3{line-height:1.5;margin:14px 0 12px}.number{font-size:12px;color:var(--muted)}.card p{color:var(--muted);font-size:13px;line-height:1.6}.card .badge{display:inline-block;border:0;padding:3px 0;color:var(--gold)}.notice{border-left:3px solid var(--gold);padding:14px 18px;background:#211f18;color:#dbd0ae;font-size:13px;line-height:1.7;margin:24px 0}.study-layout{display:grid;grid-template-columns:minmax(0,1fr) 235px;gap:30px;align-items:start}.lesson{background:#141d26;border:1px solid var(--line);border-radius:12px;padding:30px;max-width:850px}.lesson h1{font-size:30px}.lesson h2{font-size:21px;margin-top:32px;scroll-margin-top:25px}.lesson p,.lesson li{font-size:16px;line-height:1.85;color:#c7d4df}.lesson ul{padding-left:23px}.toc{position:sticky;top:25px;font-size:12px}.toc button{display:block;padding:8px 0;color:var(--muted);background:none;border:0;text-align:left}.toc button:hover{color:var(--blue)}.quiz{max-width:800px;margin:25px auto}.quiz h2{font-size:25px;line-height:1.5}.answer{display:flex;gap:15px;align-items:center;border:1px solid var(--line);border-radius:9px;padding:16px;margin:12px 0;cursor:pointer;background:#101922}.answer:has(input:checked){border-color:var(--blue);background:#123340}.answer input{accent-color:var(--blue)}fieldset{border:0;padding:0;margin:0}legend{font-size:12px;color:var(--muted);margin:12px 0}.feedback{padding:18px;border:1px solid #4b8879;background:#142e28;border-radius:9px;margin:20px 0;line-height:1.7}.incorrect{background:#33261b;border-color:#a9783c}.meter{height:5px;background:#2b3742;border-radius:5px;overflow:hidden}.meter span{display:block;background:var(--blue);height:100%}.big-score{font-size:64px;color:var(--blue);font-weight:750}.gallery img{width:100%;aspect-ratio:4/3;object-fit:contain;background:#080d11;border-radius:8px}.gallery button{width:100%;margin-top:12px}.search{background:#141d26;color:white;border:1px solid var(--line);border-radius:8px;padding:13px 16px;width:min(100%,380px);margin:15px 0 25px}dialog{background:#121d27;color:white;border:1px solid var(--line);border-radius:12px;width:95vw;max-width:1450px;height:92vh;padding:24px}dialog::backdrop{background:#000b}dialog form{text-align:right}.image-scroll{overflow:auto;height:calc(100% - 140px);background:#080d11}.image-scroll img{display:block;width:1500px;max-width:none}.empty{text-align:center;padding:45px}.stat{font-size:34px;color:var(--blue);font-weight:700}.actions{margin-top:28px}.source-note{font-size:11px;color:var(--muted);margin-top:25px}
@media(min-width:1600px){main{padding:48px 64px}}@media(max-width:1100px){.cards{grid-template-columns:repeat(2,minmax(0,1fr))}.study-layout{grid-template-columns:1fr}.toc{position:static;order:-1}.toc details{border:1px solid var(--line);padding:15px;border-radius:8px}}@media(max-width:760px){.shell{display:block}.sidebar{position:static;height:auto;padding:17px;border-right:0;border-bottom:1px solid var(--line)}.brand{font-size:19px}.brand img{width:36px;height:36px}.workspace-label,.sidebar-foot{display:none}nav{grid-template-columns:repeat(4,minmax(0,1fr));gap:4px;margin-top:17px}nav a{padding:10px 4px;font-size:11px;gap:5px;flex-direction:column;text-align:center}nav a.active{box-shadow:inset 0 -3px var(--blue)}header{height:58px;padding:0 18px;font-size:11px}main{padding:25px 18px 40px}.hero{padding:22px}.hero h2{font-size:26px}.cards{grid-template-columns:1fr}.lesson{padding:20px}.lesson p,.lesson li{font-size:15px}.section-top{align-items:flex-start}footer{padding:18px}.preview-pill{font-size:9px}.quiz h2{font-size:21px}}
.vox-panel{position:sticky;bottom:0;z-index:3;background:#142733;border-top:2px solid #47cdf5;padding:16px 30px;box-shadow:0 -8px 30px #0005}.vox-title{color:#47cdf5;font-size:21px;margin-right:12px}.vox-panel .row{margin-top:12px}.vox-panel label,.vox-panel small{font-size:12px;color:#b9cbd7}.vox-panel select{max-width:260px;background:#0b1822;color:#edf3f8;padding:9px;border:1px solid #466375;border-radius:6px}.vox-panel p{font-size:13px;margin:10px 0 5px}.vox-panel select:focus-visible{outline:3px solid #ffb400}@media(max-width:760px){.vox-panel{padding:12px 16px}.vox-panel select{max-width:180px}.vox-panel .row{gap:8px}.vox-panel button{padding:10px 12px}}
.language-bar{display:flex;align-items:center;gap:10px;padding:14px 40px;border-bottom:1px solid #2a3744;flex-wrap:wrap}.language-bar span{color:#a8b8c7;font-size:12px;margin-right:8px}.language-bar button{background:#14212b;color:#d8e8f4;border:1px solid #365364;border-radius:20px;padding:8px 15px}.language-bar button[aria-pressed=true]{background:#47cdf5;color:#07161d;border-color:#47cdf5;font-weight:700}@media(max-width:760px){.language-bar{padding:12px 18px;gap:8px}.language-bar span{width:100%}}
.disclaimer{max-width:850px;margin:auto}.disclaimer .card{margin:18px 0}.disclaimer h1{font-size:34px}.disclaimer h2{font-size:21px}.disclaimer p{line-height:1.8}.disclaimer .card p{font-size:16px;color:#c7d4df}.disclaimer .primary{white-space:normal;line-height:1.6}footer a{display:inline-block;margin-left:12px;color:#47cdf5}

/* Compact VOX launcher leaves room for the lesson. */
.vox-heading{display:flex;align-items:center;gap:10px;flex-wrap:wrap}.vox-heading .vox-title{margin-right:0}.vox-heading [data-vox-toggle]{margin-left:auto;padding:8px 14px}.vox-panel [hidden]{display:none!important}