:root {
  color-scheme: light;
  --bg: #ffffff;
  --fg: #24292f;
  --muted: #57606a;
  --border: #d0d7de;
  --link: #0969da;
  --max: 42rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;
    --bg: #0d1117;
    --fg: #e6edf3;
    --muted: #8b949e;
    --border: #30363d;
    --link: #58a6ff;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0 auto;
  padding: 2rem 1rem;
  max-width: var(--max);
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }

h1 { font-size: 1.6rem; line-height: 1.2; }