* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Arial', sans-serif;
}

body {
    background-color: #f5f5f5;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

h1 {
    text-align: center;
    margin-bottom: 30px;
    color: #2c3e50;
}

.card {
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    padding: 30px;
    margin-bottom: 30px;
}

h2 {
    margin-bottom: 20px;
    color: #3498db;
    font-size: 1.5rem;
}

.product-selection {
    margin-bottom: 25px;
}

select, input {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;
    margin-top: 8px;
}

select:focus, input:focus {
    outline: none;
    border-color: #3498db;
    box-shadow: 0 0 0 2px rgba(52, 152, 219, 0.2);
}

.input-group {
    margin-bottom: 20px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: bold;
    color: #555;
}

button {
    background-color: #3498db;
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    width: 100%;
    transition: background-color 0.3s;
}

button:hover {
    background-color: #2980b9;
}

button:disabled {
    background-color: #95a5a6;
    cursor: not-allowed;
}

.hidden {
    display: none;
}

#result-container {
    margin-top: 20px;
    padding: 15px;
    border-radius: 4px;
}

.success {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.error {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.footer {
    text-align: center;
    margin-top: 30px;
    color: #7f8c8d;
    font-size: 14px;
}

.spinner {
    border: 4px solid rgba(0, 0, 0, 0.1);
    width: 36px;
    height: 36px;
    border-radius: 50%;
    border-left-color: #3498db;
    animation: spin 1s linear infinite;
    margin: 0 auto 15px;
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}

#loading {
    text-align: center;
    margin: 20px 0;
}

#loading p {
    color: #7f8c8d;
}