:root { color-scheme: light dark; }
body { margin: 0; min-height: 100vh; display: grid; place-items: center;
       font: 16px/1.5 system-ui, sans-serif; background: #f6f7f9; color: #1d2330; }
@media (prefers-color-scheme: dark) { body { background: #14171d; color: #e6e9ef; } }
main { padding: 2rem 1rem; text-align: center; max-width: 32rem; }
h1 { font-size: 1.5rem; margin: 0 0 .5rem; }
p { margin: 0; opacity: .75; }