:root { color-scheme: light dark; }
body { margin: 0; min-height: 100vh; display: grid; place-items: center;
  font: 17px/1.5 system-ui, -apple-system, "Segoe UI", sans-serif;
  background: #fcfcfb; color: #0b0b0b; }
@media (prefers-color-scheme: dark) { body { background: #1a1a19; color: #fff; } }
main { max-width: 22rem; padding: 1.5rem; text-align: center; }
h1 { font-size: 1.6rem; margin: 0 0 .5rem; }
p { margin: .4rem 0; opacity: .8; }