:root {
  color-scheme: light dark;
  --bg: #fff;
  --fg: #1a1a1a;
  --muted: #666;
  --border: #ddd;
  --accent: #1a4fa0;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14161a;
    --fg: #e8e8e8;
    --muted: #999;
    --border: #333;
    --accent: #6fa0e8;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: 0 16px 32px;
  background: var(--bg);
  color: var(--fg);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 14px;
  line-height: 1.5;
}

a { color: var(--accent); }

header {
  padding: 12px 0 8px;
  border-bottom: 1px solid var(--border);
}

h1 { font-size: 18px; margin: 0; }
h1 a { color: var(--fg); text-decoration: none; }

main {
  max-width: 640px;
  margin: 0 auto;
}

h2 { font-size: 20px; margin: 16px 0 12px; }
h3 { font-size: 15px; margin: 20px 0 6px; }
p { margin: 0 0 10px; }
code {
  background: var(--border);
  padding: 1px 4px;
  border-radius: 3px;
  font-size: 0.9em;
}

footer {
  max-width: 640px;
  margin: 24px auto 0;
  color: var(--muted);
  font-size: 12px;
  border-top: 1px solid var(--border);
  padding-top: 8px;
}