:root{color-scheme:dark}body{margin:0;min-height:100vh;display:grid;place-items:center;font-family:system-ui,sans-serif;background:radial-gradient(ellipse at top,#1b2735,#090a0f);color:#e6edf3}.card{text-align:center;padding:2.5rem 3rem;border:1px solid #ffffff14;border-radius:16px;background:#ffffff08}button{margin-top:1rem;padding:.6rem 1.4rem;border:0;border-radius:8px;background:linear-gradient(135deg,#6366f1,#06b6d4);color:#fff;font-weight:600;cursor:pointer}