.container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: #f5f5f5;
}

#openPaymentModal {
    padding: 12px 24px;
    font-size: 16px;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

#openPaymentModal:hover {
    background-color: #45a049;
}