body{margin:0;padding:2rem;font-family:-apple-system,BlinkMacSystemFont,Inter,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,Arial,sans-serif;background-color:#0f172a;color:#f8fafc;text-align:center}button{margin:6px;background-color:#2563eb;color:#fff;padding:10px 20px;border:none;border-radius:8px;font-weight:700;cursor:pointer;transition:background-color .2s ease}button:hover{background-color:#3b82f6}