body {
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
    background: #222;
    color: white;
    transition: background 0.3s;
}

.container {
    max-width: 700px;
    margin: 60px auto;
    text-align: center;
}

.card {
    background: rgba(255,255,255,0.1);
    margin: 20px 0;
    padding: 20px;
    border-radius: 10px;
}

button {
    padding: 10px 20px;
    font-size: 16px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
}

button:hover {
    opacity: 0.9;
}