:root{--brand:#2563EB;--brand-ink:#1e40af;--bg:#f7f8fb;--surface:#fff;--text:#0f172a;--muted:#5b6475;--line:#e3e7ef}
@media (prefers-color-scheme:dark){:root{--bg:#0b1020;--surface:#131a2e;--text:#e8ecf6;--muted:#9aa4ba;--line:#24304d;--brand-ink:#93b4ff}}
*{box-sizing:border-box}
body{margin:0;font:16px/1.6 system-ui,-apple-system,"Segoe UI",sans-serif;background:var(--bg);color:var(--text)}
a{color:var(--brand-ink)}
header,footer,main{max-width:880px;margin:0 auto;padding:0 16px}
header{display:flex;justify-content:space-between;align-items:center;padding-top:20px;padding-bottom:20px;gap:12px;flex-wrap:wrap}
.logo{font-weight:800;text-decoration:none;color:var(--text);display:flex;gap:10px;align-items:center}
.mark{width:28px;height:28px;border-radius:8px;background:var(--brand)}
nav a{margin-left:16px;text-decoration:none;color:var(--muted)}
nav a:hover,nav a:focus-visible{color:var(--text)}
.hero{padding:56px 0 40px}
.hero h1{font-size:clamp(2.2rem,1.5rem + 3vw,3.6rem);line-height:1.1;margin:0 0 12px;letter-spacing:-.02em}
.hero p{font-size:1.2rem;color:var(--muted);max-width:36ch}
.btn{display:inline-block;padding:12px 20px;border-radius:10px;background:var(--brand);color:#fff;text-decoration:none;font-weight:600;border:0;margin:4px 8px 4px 0}
.btn:hover{filter:brightness(1.1)}
.btn.ghost{background:transparent;color:var(--text);border:1px solid var(--line)}
.btn[aria-disabled=true]{background:var(--line);color:var(--muted);pointer-events:none}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:16px;margin:32px 0}
.card{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:20px}
.card h3{margin:0 0 6px}
.card p{margin:0;color:var(--muted)}
.prose{padding:24px 0 48px}
.prose h1{margin-top:0}
footer{border-top:1px solid var(--line);padding-top:20px;padding-bottom:40px;color:var(--muted);font-size:.9rem}
footer a{color:var(--muted);margin-right:14px}