body {
    font-family: Arial, sans-serif;
    background-color: #f4f6f9;
    color: #333;
    margin: 0;
    padding: 16px;
    line-height: 1.25;
}

.container {
    max-width: 500px;
    margin: 0 auto;
    background: #ffffff;
    padding: 24px;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
}

header h2 {
    margin-top: 0;
    color: #1565C0;
    font-size: 1.4rem;
}

#card-info {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 20px;
}

.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    margin-bottom: 6px;
    font-weight: bold;
    font-size: 0.95rem;
}

.form-group select,
.form-group input,
.form-group textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 1rem;
    box-sizing: border-box;
}

.price-box {
    background: #e3f2fd;
    padding: 12px;
    border-radius: 8px;
    text-align: center;
    margin-bottom: 20px;
    font-size: 1.1rem;
}

.price-box strong {
    color: #0d47a1;
    font-size: 1.3rem;
}

.btn-submit {
    background-color: #1565C0;
    color: white;
    border: none;
    width: 100%;
    padding: 12px;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    font-weight: bold;
}

.btn-submit:hover {
    background-color: #0d47a1;
}