.hero{max-width:780px;padding:3.5rem 0 2rem}.hero h1{letter-spacing:-.02em;font-size:clamp(1.8rem,4vw,2.6rem)}.lead{color:var(--fg-muted);font-size:1.12rem}.stats{color:var(--fg-muted);flex-wrap:wrap;gap:1.5rem;margin-top:1.25rem;display:flex}.stats strong{color:var(--fg);font-size:1.2rem}.layout{grid-template-columns:220px 1fr;align-items:start;gap:2rem;display:grid}.toc-wrap{position:sticky;top:76px}.toc-title{text-transform:uppercase;letter-spacing:.06em;color:var(--fg-faint);margin:0 0 .5rem;font-size:.8rem}.toc{color:var(--fg-faint);margin:0;padding-left:1.4rem;font-size:.93rem}.toc li{margin:.2rem 0}.toc a{color:var(--fg-muted)}.toc a:hover{color:var(--accent)}.toc .dot{background:var(--accent);vertical-align:middle;border-radius:50%;width:7px;height:7px;margin-left:.4rem;display:inline-block}.chapters{flex-direction:column;gap:1.25rem;display:flex}.chapter{padding:1.5rem;scroll-margin-top:76px}.chapter-head{align-items:flex-start;gap:1rem;display:flex}.chapter-head h2{margin:0 0 .25rem}.chapter-head p{margin:0}.chapter-number{font-family:var(--font-mono);color:var(--accent);background:var(--accent-soft);border-radius:var(--radius-sm);flex-shrink:0;padding:.2rem .5rem;font-size:1.1rem;font-weight:600}.concepts{flex-wrap:wrap;gap:.4rem;margin:1rem 0 0;padding:0;list-style:none;display:flex}.concepts li{border:1px solid var(--border);color:var(--fg-muted);border-radius:999px;padding:.1rem .6rem;font-size:.8rem}.demos{grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:.75rem;margin-top:1rem;display:grid}.demo{border-radius:var(--radius-sm);color:var(--fg);border:1px solid var(--accent);background:var(--accent-soft);flex-direction:column;padding:.9rem 1rem;transition:transform .12s,box-shadow .12s;display:flex}.demo:hover{box-shadow:var(--shadow);text-decoration:none;transform:translateY(-2px)}.demo h4{margin:0 0 .25rem;font-size:1rem}.demo p{color:var(--fg-muted);margin:0;font-size:.88rem;line-height:1.5}.demo-open{color:var(--accent);margin-top:auto;padding-top:.6rem;font-size:.9rem;font-weight:600}@media (width<=820px){.layout{grid-template-columns:1fr}.toc-wrap{display:none}}