:root{color-scheme:light dark;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif}body{margin:0;min-height:100vh;display:flex;align-items:center;justify-content:center;background:#f5f5f4}@media (prefers-color-scheme: dark){body{background:#1c1c1c}}.card{width:100%;max-width:440px;padding:32px;text-align:center}.card h1{font-size:1.5rem;margin:0 0 8px}.card .sub{margin:0 0 24px;opacity:.7}