:root{--bg:#fff;--fg:#1d1d1f;--muted:#6e6e73;--card:#f5f5f7;--accent:#0a84ff;color-scheme:light dark}
@media (prefers-color-scheme:dark){:root{--bg:#000;--fg:#f5f5f7;--muted:#a1a1a6;--card:#1c1c1e}}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--fg);font:17px/1.55 -apple-system,BlinkMacSystemFont,"SF Pro Text","Helvetica Neue",Arial,sans-serif}
main{max-width:720px;margin:0 auto;padding:32px 20px 64px}
nav{display:flex;gap:18px;align-items:center;max-width:720px;margin:0 auto;padding:18px 20px 0}
nav a{color:var(--muted);text-decoration:none}nav a.home{color:var(--fg);font-weight:600;margin-right:auto}
h1{font-size:34px;line-height:1.15;margin:24px 0 8px}h2{font-size:21px;margin:32px 0 6px}h3{font-size:17px;margin:20px 0 2px}
p,li{color:var(--fg)}.muted{color:var(--muted)}a{color:var(--accent)}
.card{background:var(--card);border-radius:14px;padding:16px 18px;margin:20px 0}
footer{max-width:720px;margin:0 auto;padding:0 20px 40px;color:var(--muted);font-size:14px}footer a{color:var(--muted)}