body { font-family: system-ui, sans-serif; background: #111; color: #eee; display: grid; place-items: center; min-height: 100vh; margin: 0; }
main { width: min(420px, 90vw); }
input, button { font: inherit; padding: 8px 12px; border-radius: 8px; border: 1px solid #333; }
button { background: #f90; color: #111; cursor: pointer; }