:root {
  --bg: #fbfaf7;
  --fg: #1f2328;
  --muted: #6a6f76;
  --link: #0b6bcb;
  --rule: #e4e1da;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15171a;
    --fg: #e8e6e3;
    --muted: #9aa0a6;
    --link: #6cb4ff;
    --rule: #2c3036;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 17px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}
main { max-width: 680px; margin: 0 auto; padding: 48px 16px 24px; }
h1 { font-size: 2rem; line-height: 1.2; margin: 0 0 8px; }
h2 { font-size: 1.15rem; margin: 32px 0 8px; }
a { color: var(--link); }