* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    color: #333;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 40px;
}

h1 {
    font-size: 2.5rem;
    color: #2c3e50;
    margin-bottom: 10px;
}

.subtitle {
    color: #7f8c8d;
    font-size: 1.1rem;
}

main {
    background: white;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    padding: 40px;
}

.input-section {
    margin-bottom: 40px;
}

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

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #34495e;
}

select, input[type="text"] {
    width: 100%;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.3s;
}

select:focus, input[type="text"]:focus {
    outline: none;
    border-color: #3498db;
}

input[type="range"] {
    width: 200px;
    margin-right: 10px;
}

.hint {
    display: block;
    margin-top: 5px;
    color: #7f8c8d;
    font-size: 0.9rem;
}

.checkbox-group {
    display: flex;
    align-items: center;
}

.checkbox-group label {
    display: flex;
    align-items: center;
    margin-bottom: 0;
}

.checkbox-group input[type="checkbox"] {
    margin-right: 8px;
    width: auto;
}

.generate-btn {
    width: 100%;
    padding: 15px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

.generate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.generate-btn:active {
    transform: translateY(0);
}

.output-section {
    margin-bottom: 40px;
}

.barcode-container {
    background: #f8f9fa;
    border: 2px dashed #dee2e6;
    border-radius: 10px;
    padding: 40px;
    text-align: center;
    min-height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.placeholder {
    color: #adb5bd;
    font-size: 1.2rem;
}

#barcodeSvg {
    max-width: 100%;
    height: auto;
}

.action-buttons {
    margin-top: 20px;
    display: flex;
    gap: 10px;
    justify-content: center;
    flex-wrap: wrap;
}

.action-btn {
    padding: 10px 20px;
    background: #3498db;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    cursor: pointer;
    transition: background 0.3s;
}

.action-btn:hover {
    background: #2980b9;
}

.error-message {
    margin-top: 10px;
    padding: 10px;
    background: #fee;
    color: #c33;
    border-radius: 8px;
    display: none;
}

.info-section {
    margin-top: 40px;
}

.info-section h2 {
    color: #2c3e50;
    margin-bottom: 20px;
}

.format-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.format-item {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 10px;
    border-left: 4px solid #3498db;
}

.format-item h3 {
    color: #34495e;
    margin-bottom: 10px;
}

.format-item p {
    color: #7f8c8d;
    font-size: 0.95rem;
}

@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    main {
        padding: 20px;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    input[type="range"] {
        width: 150px;
    }
}