:root {
  --bg: #ffffff;
  --text: #1b1f24;
  --muted: #5b6573;
  --link: #3d2df5;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1117;
    --text: #e6edf3;
    --muted: #8b949e;
    --link: #9b8fff;
  }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 32px 16px 64px;
}

h1 { font-size: 28px; line-height: 1.2; }
h2 { font-size: 20px; margin-top: 32px; }
h3 { font-size: 17px; margin-bottom: 4px; }
a { color: var(--link); }
.muted { color: var(--muted); }