:root {
  --bg: #ffffff;
  --fg: #18181b;
  --muted: #52525b;
  --rule: #e4e4e7;
  --link: #2563eb;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #09090b;
    --fg: #fafafa;
    --muted: #a1a1aa;
    --rule: #27272a;
    --link: #60a5fa;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.65 Inter, -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang HK', 'Microsoft JhengHei', sans-serif;
}
main { max-width: 680px; margin: 0 auto; padding: 56px 16px 80px; }
h1 { font-size: 2rem; line-height: 1.2; margin: 0 0 12px; }
h2 { font-size: 1.15rem; margin: 40px 0 8px; }
p, li { color: var(--fg); }
.lead { font-size: 1.15rem; color: var(--muted); margin: 0 0 32px; }
.muted { color: var(--muted); font-size: 0.9rem; }
a { color: var(--link); }
ul { padding-left: 1.25rem; }
footer { border-top: 1px solid var(--rule); margin-top: 56px; padding-top: 16px; }
footer a { margin-right: 16px; }