:root { color-scheme: light dark; }
body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
main { padding: 2rem; text-align: center; }
h1 { font-size: clamp(1.6rem, 5vw, 2.5rem); margin: 0 0 .5rem; }
p  { margin: 0; opacity: .75; }