#checkout-form {
    max-width: 500px;
    padding: 20px;
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
    font-family: Arial, sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

#checkout-form h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: #333;
    text-align: center;
}

#checkout-form > div {
    min-width: 80%;
    margin: 0 auto;
}

#checkout-form p {
    font-size: 0.9rem;
    color: #666;
    text-align: center;
}

#checkout-form label {
    font-weight: bold;
    color: #444;
    display: block;
    margin-bottom: 5px;
}

#checkout-form span {
    display: block;
    font-size: 1rem;
    color: #333;
    margin-bottom: 8px;
}

#checkout-form input {
    width: 100%;
    padding: 10px;
    font-size: 1rem;
    border: 1px solid #ccc;
    border-radius: 5px;
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.1);
    box-sizing: border-box;
}

#checkout-form input[type="number"]:focus {
    outline: none;
    border-color: #007bff;
    box-shadow: 0 0 5px rgba(0, 123, 255, 0.5);
}

#checkout-form .button {
    width: 100%;
    padding: 10px;
    font-size: 1.1rem;
    border-radius: 5px;
    cursor: pointer;
}

/* Responsive */
@media (max-width: 600px) {
    #checkout-form {
        padding: 15px;
    }

    #checkout-form h3 {
        font-size: 1.3rem;
    }
}