body {
    font-family: Arial;
    text-align: center;
    background: #0f172a;
    color: white;
}

button {
    display: block;
    margin: 10px auto;
    padding: 15px;
    font-size: 16px;
    background: #22c55e;
    border: none;
    border-radius: 8px;
    color: white;
}