:root{--ivory:#faf9f5;--paper:#f0eee6;--ink:#141413;--muted:#5e5d59;--soft:#87867f;--line:#e6e3d9;--clay:#d97757;--clay2:#c6613f;--white:#fff;--side:312px;--top:60px}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:calc(var(--top) + 16px)}
body{margin:0;background:var(--ivory);color:var(--ink);font:16px/1.5 Inter,system-ui,sans-serif;-webkit-font-smoothing:antialiased}
a{color:inherit}
h1,h2{letter-spacing:-.02em;text-wrap:balance}
button{font:inherit;color:inherit;cursor:pointer}
:focus-visible{outline:2px solid var(--clay2);outline-offset:2px;border-radius:4px}

/* top bar */
.top{position:sticky;top:0;z-index:20;height:var(--top);display:flex;align-items:center;justify-content:space-between;gap:16px;padding:0 24px;background:rgba(250,249,245,.92);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}
.logo{display:flex;align-items:center;gap:9px;font-weight:800;font-size:16px;text-decoration:none;white-space:nowrap}
.logo em{font-style:normal;font-weight:500;color:var(--muted)}
.mark{width:18px;height:18px;border-radius:5px;background:var(--clay)}
.top nav{display:flex;align-items:center;gap:20px;font-size:14px;min-width:0}
.top nav a{text-decoration:none;color:var(--muted);white-space:nowrap}
.top nav a:hover{color:var(--ink)}
.top nav .signin{color:var(--ink);font-weight:600;border:1px solid var(--line);background:var(--white);padding:7px 14px;border-radius:8px}
.who{color:var(--ink);font-weight:500;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;max-width:220px}
.badge{font-size:11px;font-weight:700;letter-spacing:.05em;text-transform:uppercase;border-radius:5px;padding:2px 7px;background:var(--ink);color:var(--ivory);white-space:nowrap}

/* shared */
.wrap{max-width:1016px;margin:0 auto;padding:64px 24px 96px}
.kicker{margin:0;font-size:12px;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:var(--clay2)}
.wrap h1{font-weight:800;font-size:clamp(30px,5vw,46px);line-height:1.08;margin:10px 0 14px}
.lede{font-size:18px;color:var(--muted);max-width:60ch;margin:0}
.fine{font-size:14px;color:var(--muted);margin:14px 0 0}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:1px solid var(--ink);background:var(--ink);color:var(--ivory);font-weight:600;font-size:15px;padding:12px 20px;border-radius:10px;text-decoration:none;transition:background .15s,border-color .15s}
.btn:hover{background:#2b2a27}
.btn.ghost{background:transparent;color:var(--ink);border-color:var(--line)}
.btn.ghost:hover{border-color:var(--ink);background:transparent}
.prog{display:flex;align-items:center;gap:12px;font-size:13px;color:var(--muted)}
.prog span{white-space:nowrap}
.prog b{color:var(--ink)}
.pbar{flex:1;height:6px;border-radius:99px;background:var(--line);overflow:hidden}
.pbar i{display:block;height:100%;border-radius:99px;background:var(--clay);transition:width .3s}
.num{flex:none;width:24px;height:24px;border-radius:50%;border:1.500px solid var(--line);background:var(--white);display:grid;place-items:center;font-size:12px;font-weight:600;color:var(--muted)}
.num i{font-style:normal}
.num svg{display:none}
.done .num{background:var(--clay);border-color:var(--clay);color:#fff}
.done .num svg{display:block}
.done .num i{display:none}

/* hub */
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin-top:36px}
.card{background:var(--white);border:1px solid var(--line);border-radius:16px;padding:18px;display:flex;flex-direction:column;gap:10px;text-decoration:none;transition:border-color .15s,transform .15s}
.card:hover{border-color:var(--clay);transform:translateY(-2px)}
.cover{height:112px;border-radius:10px;background:var(--ink);color:var(--ivory);display:flex;align-items:flex-end;padding:12px;font-weight:800;font-size:22px;letter-spacing:-.02em}
.card h2{font-size:18px;margin:4px 0 0}
.card p{margin:0;font-size:15px;color:var(--muted)}
.card .meta{display:flex;flex-wrap:wrap;align-items:center;gap:6px 12px;font-size:13px;color:var(--muted);margin-top:auto;padding-top:6px}

/* course overview */
.hero{display:grid;grid-template-columns:1fr 340px;gap:40px;align-items:start;margin-bottom:28px}
.box{background:var(--white);border:1px solid var(--line);border-radius:16px;padding:20px;display:flex;flex-direction:column;gap:14px}
.box .stat{margin:0;font-size:14px;color:var(--muted)}
.box .fine{margin:0;text-align:center}
.part{margin-top:36px}
.part h2{font-size:20px;margin:0 0 10px;display:flex;align-items:baseline;gap:12px}
.part h2 span{font-size:12px;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:var(--soft)}
.row{display:flex;align-items:center;gap:14px;padding:14px 16px;background:var(--white);border:1px solid var(--line);text-decoration:none;margin-top:-1px;transition:background .12s}
.row:first-of-type{border-radius:12px 12px 0 0}
.row:last-of-type{border-radius:0 0 12px 12px}
.row:hover{background:#fdfcf9}
.row .txt{flex:1;min-width:0;display:flex;flex-direction:column;gap:2px}
.row .txt b{font-weight:600}
.row .txt small{font-size:14px;color:var(--muted)}
.row .mins{font-size:13px;color:var(--soft);white-space:nowrap}

/* lesson */
.layout{display:grid;grid-template-columns:var(--side) minmax(0,1fr)}
.side{position:sticky;top:var(--top);height:calc(100vh - var(--top));overflow-y:auto;border-right:1px solid var(--line);background:var(--paper);padding:22px 14px 32px}
.side .ct{display:block;font-weight:800;font-size:17px;letter-spacing:-.01em;text-decoration:none;padding:0 8px 10px}
.side .prog{padding:0 8px 6px}
.ph{margin:20px 8px 6px;font-size:11px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--soft)}
.sl{display:flex;align-items:center;gap:10px;padding:8px;border-radius:9px;text-decoration:none;font-size:14.500px;line-height:1.3;color:var(--ink)}
.sl:hover{background:rgba(20,20,19,.05)}
.sl.on{background:var(--white);box-shadow:0 0 0 1px var(--line);font-weight:600}
.sl .t{flex:1;min-width:0}
.sl .m{font-size:12px;color:var(--soft)}
.sl .lock{display:grid;place-items:center}
.lesson{max-width:760px;width:100%;margin:0 auto;padding:44px 32px 96px}
.menu{display:none}
.crumb{margin:0;font-size:13px;color:var(--muted)}
.crumb a{color:var(--clay2);font-weight:600;text-decoration:none}
.lesson h1{font-weight:800;font-size:clamp(30px,4.600vw,42px);line-height:1.1;margin:10px 0 14px}
.lmeta{display:flex;flex-wrap:wrap;gap:8px;margin:0 0 30px;font-size:13px;color:var(--muted)}
.lmeta span{border:1px solid var(--line);background:var(--white);border-radius:99px;padding:4px 11px}
.lmeta .plan{background:var(--paper)}

.prose{font-size:17px;line-height:1.68}
.prose section{margin-top:38px}
.prose section:first-child{margin-top:0}
.prose h2{font-size:24px;line-height:1.2;margin:0 0 12px}
.prose p{margin:0 0 16px}
.prose ul,.prose ol{margin:0 0 16px;padding-left:24px}
.prose li{margin-bottom:7px}
.prose li::marker{color:var(--soft)}
.prose code{font:.880em ui-monospace,SFMono-Regular,Menlo,monospace;background:var(--paper);border-radius:5px;padding:2px 5px}
.prose .outline{background:var(--white);border:1px solid var(--line);border-radius:14px;padding:18px 22px 6px}
.prose .outline h2{font-size:12px;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:var(--soft);margin-bottom:10px}
.prose .outline ul{font-size:16px}
.prose .try,.prose .remember{border-radius:14px;padding:22px 24px 8px}
.prose .try{background:#fbeee8;border:1px solid #f1d2c5}
.prose .remember{background:var(--paper);border:1px solid var(--line)}
.prose .try h2,.prose .remember h2{font-size:19px}
.prompt{position:relative;margin:4px 0 20px;background:var(--ink);color:#f3f1ea;border-radius:12px}
.prompt pre{margin:0;padding:18px 20px;padding-right:76px;font:14.500px/1.6 ui-monospace,SFMono-Regular,Menlo,monospace;white-space:pre-wrap;overflow-wrap:anywhere}
.copy{position:absolute;top:10px;right:10px;border:1px solid rgba(255,255,255,.22);background:rgba(255,255,255,.08);color:#f3f1ea;font-size:12px;font-weight:600;border-radius:7px;padding:5px 10px}
.copy:hover{background:rgba(255,255,255,.18)}
.shot{margin:6px 0 24px}
.shot img{display:block;width:100%;height:auto;border:1px solid var(--line);border-radius:12px;background:var(--white);box-shadow:0 8px 28px -14px rgba(20,20,19,.25)}
.shot.narrow{max-width:72%;margin-left:auto;margin-right:auto}
.table{overflow-x:auto;margin:4px 0 20px;border:1px solid var(--line);border-radius:12px;background:var(--white)}
.table table{width:100%;border-collapse:collapse;font-size:15px;line-height:1.45}
.table th,.table td{text-align:left;vertical-align:top;padding:11px 14px;border-bottom:1px solid var(--line)}
.table th{background:var(--paper);font-size:13px;font-weight:700}
.table tr:last-child td{border-bottom:0}
.checks{list-style:none;padding:0!important}
.checks label{display:flex;gap:11px;align-items:flex-start;cursor:pointer}
.checks input{flex:none;width:18px;height:18px;margin:5px 0 0;accent-color:var(--clay2)}
.checks input:checked+span{color:var(--soft);text-decoration:line-through}

.prose.cut{position:relative}
.prose.cut::after{content:"";position:absolute;left:0;right:0;bottom:0;height:120px;background:linear-gradient(rgba(250,249,245,0),var(--ivory));pointer-events:none}
.wall{margin-top:8px;background:var(--white);border:1px solid var(--line);border-radius:18px;padding:32px 28px;text-align:center}
.wall .lk{display:inline-grid;place-items:center;width:40px;height:40px;border-radius:50%;background:var(--paper);color:var(--clay2)}
.wall .lk svg{width:18px;height:18px}
.wall h2{font-size:24px;margin:14px 0 8px}
.wall p{margin:0 auto;max-width:44ch;color:var(--muted)}
.acts{display:flex;flex-wrap:wrap;justify-content:center;gap:10px;margin-top:20px}
.finish{display:flex;flex-wrap:wrap;align-items:center;gap:16px;margin-top:44px;padding-top:28px;border-top:1px solid var(--line)}
.undo{border:0;background:none;padding:0;font-size:14px;color:var(--muted);text-decoration:underline}
.pn{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-top:28px}
.pn a{display:flex;flex-direction:column;gap:3px;padding:14px 16px;border:1px solid var(--line);border-radius:12px;background:var(--white);text-decoration:none;font-weight:600;font-size:15px;line-height:1.3}
.pn a:hover{border-color:var(--clay)}
.pn small{font-size:12px;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--soft)}
.pn .nx{text-align:right}

/* sign in */
.auth{max-width:520px;padding-top:72px}
.panel{background:var(--white);border:1px solid var(--line);border-radius:18px;padding:32px 28px}
.panel h1{font-size:30px;margin:0 0 10px}
.panel .lede{font-size:16px}
.panel form{display:flex;flex-direction:column;gap:8px;margin-top:22px}
.panel label{font-size:13px;font-weight:600}
.panel input[type=email]{font:inherit;padding:12px 14px;border:1px solid var(--line);border-radius:10px;background:var(--ivory);margin-bottom:8px}
.panel input[type=email]:focus{outline:2px solid var(--clay);outline-offset:0;border-color:var(--clay)}
.err{margin:16px 0 0;font-size:14px;color:#a3341b}
.dev{margin:18px 0 0;padding:12px 14px;border:1px dashed var(--clay);border-radius:10px;font-size:14px;overflow-wrap:anywhere}

@media(max-width:900px){
  .hero{grid-template-columns:1fr;gap:24px}
  .cards{grid-template-columns:repeat(2,1fr)}
  .layout{grid-template-columns:minmax(0,1fr)}
  .side{position:fixed;inset:var(--top) 0 0 0;height:auto;z-index:15;border-right:0;display:none}
  .side.open{display:block}
  .menu{display:inline-flex;align-items:center;margin-bottom:18px;border:1px solid var(--line);background:var(--white);border-radius:8px;padding:7px 12px;font-size:14px;font-weight:600}
  .lesson{padding:24px 16px 72px}
}
@media(max-width:620px){
  .top{padding:0 16px}
  .top nav{gap:14px}
  .top nav a[href^="https"],.who{display:none}
  .wrap{padding:40px 16px 64px}
  .cards{grid-template-columns:1fr}
  .row{padding:12px}
  .row .txt small{display:none}
  .prose{font-size:16.500px}
  .shot.narrow{max-width:100%}
  .pn{grid-template-columns:1fr}
  .pn .nx{text-align:left}
  .wall{padding:26px 18px}
}
@media(prefers-reduced-motion:reduce){*{transition:none!important}}