:root {
  --bg: #ffffff;
  --text: #1f2328;
  --muted: #59636e;
  --link: #0969da;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1117;
    --text: #e6edf3;
    --muted: #9198a1;
    --link: #4493f8;
  }
}

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

main {
  max-width: 680px;
  margin: 0 auto;
  padding: 48px 16px;
}

h1 { font-size: 1.75rem; margin: 0 0 16px; }
h2 { font-size: 1.1rem; margin: 28px 0 8px; }
a { color: var(--link); }
.meta, footer { color: var(--muted); font-size: 0.9rem; }
footer { margin-top: 40px; }