:root { color-scheme: light dark; }
body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  background: #f6f8fa;
  color: #1c2733;
}
main { max-width: 34rem; padding: 2rem; text-align: center; }
h1 { font-size: clamp(1.8rem, 5vw, 2.6rem); margin: 0 0 0.75rem; }
p { margin: 0; line-height: 1.6; color: #5b6b7b; }
@media (prefers-color-scheme: dark) {
  body { background: #16181d; color: #e8ecf1; }
  p { color: #9aa7b4; }
}