:root{--bg:#fff;--fg:#1d1d1f;--muted:#5f6368;--accent:#e60012;--card:#f5f5f7}
@media (prefers-color-scheme:dark){:root{--bg:#111;--fg:#f2f2f2;--muted:#a0a0a0;--card:#1c1c1e}}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--fg);font:16px/1.6 system-ui,-apple-system,"Segoe UI",Roboto,sans-serif}
main{max-width:720px;margin:0 auto;padding:32px 16px 64px}
h1{font-size:1.8rem;line-height:1.2;margin:0 0 4px}
h2{font-size:1.2rem;margin:32px 0 8px}
.sub{color:var(--muted);margin:0 0 24px}
.card{background:var(--card);border-radius:12px;padding:16px 20px;margin:16px 0}
a{color:var(--accent)}
.btn{display:inline-block;background:var(--accent);color:#fff;text-decoration:none;padding:10px 18px;border-radius:8px;font-weight:600}
nav{display:flex;gap:16px;margin-bottom:24px;font-size:.95rem}
hr{border:0;border-top:1px solid var(--card);margin:40px 0 16px}
footer{color:var(--muted);font-size:.85rem}