:root {
  color-scheme: light dark;
  --bg: #fafafa;
  --fg: #1a1a1a;
  --muted: #555;
  --link: #0066cc;
  --border: #e5e5e5;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111;
    --fg: #f2f2f2;
    --muted: #aaa;
    --link: #6eb6ff;
    --border: #333;
  }
}
* { box-sizing: border-box; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.55;
  max-width: 42rem;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 3rem;
  background: var(--bg);
  color: var(--fg);
}
header { margin-bottom: 2rem; border-bottom: 1px solid var(--border); padding-bottom: 1rem; }
h1 { font-size: 1.5rem; margin: 0 0 0.25rem; }
.subtitle { color: var(--muted); margin: 0; font-size: 0.95rem; }
nav { margin-top: 1rem; font-size: 0.9rem; }
nav a { margin-right: 1rem; }
a { color: var(--link); }
h2 { font-size: 1.1rem; margin-top: 1.75rem; }
p, li { font-size: 0.95rem; }
ul { padding-left: 1.25rem; }
footer { margin-top: 2.5rem; padding-top: 1rem; border-top: 1px solid var(--border); font-size: 0.85rem; color: var(--muted); }