:root { color-scheme: light dark; }
  body { font-family: system-ui, sans-serif; margin: 0; min-height: 100vh; display: grid; place-items: center; }
  main { max-width: 40rem; padding: 2rem; text-align: center; }
  h1 { font-size: 1.5rem; margin: 0 0 .5rem; }
  p  { margin: .25rem 0; }