body {
    font-family: Arial, sans-serif;
    background: #f4f4f4;
    padding: 20px;
}
.container {
    background: white;
    padding: 20px;
    border-radius: 10px;
    max-width: 500px;
    margin: auto;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}
button {
    margin-top: 10px;
    padding: 8px 12px;
    border: none;
    background: #007bff;
    color: white;
    border-radius: 5px;
    cursor: pointer;
}
button:hover {
    background: #0056b3;
}
.hidden {
    display: none;
}