body { margin: 0; background: #fff; color: #111; font: 18px/1.5 system-ui, sans-serif; }
main { max-width: 40rem; margin: 0 auto; padding: 2rem 16px; }
a { color: #0b5cad; }
@media (prefers-color-scheme: dark) {
  body { background: #111; color: #eee; }
  a { color: #7db4f0; }
}