:root{--bg:#f4f5f7;--surface:#fff;--text:#171a21;--muted:#687082;--line:#e3e6eb;--accent:#c8102e;color-scheme:light}
@media (prefers-color-scheme:dark){:root{--bg:#0f1115;--surface:#181b22;--text:#e9ebf0;--muted:#9198a8;--line:#2b303a;--accent:#ff4d63;color-scheme:dark}}
body{margin:0;background:var(--bg);color:var(--text);font:16px/1.6 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Arial,sans-serif}
main{max-width:760px;margin:0 auto;padding:32px 16px 64px}
.card{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:24px 24px 12px}
h1{font-size:26px;margin:0 0 16px}h2{font-size:18px;margin:28px 0 8px}
a{color:var(--accent)}p,li{color:var(--text)}.muted{color:var(--muted);font-size:14px}
.back{display:inline-block;margin-bottom:16px;text-decoration:none}