:root { color-scheme: light dark; }
body {
  margin: 0;
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", sans-serif;
  display: grid;
  place-items: center;
  min-height: 100vh;
}
main { max-width: 40rem; padding: 2rem; }
h1 { font-size: 2rem; margin-bottom: 0.5rem; }
.note { color: #666; font-size: 0.9rem; }
.note::before { content: ""; }