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

body {
    font-family: 'Microsoft YaHei', 'Segoe UI', sans-serif;
    color: #333;
    line-height: 1.6;
    background-color: #f9f9f9;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}


.promo-banner {
    background: linear-gradient(135deg, #1a5276 0%, #3498db 100%);
    color: white;
    padding: 40px 0;
    position: relative;
    overflow: hidden;
}

.banner-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    position: relative;
    z-index: 2;
}

.banner-text h1 {
    font-size: 2.2rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: #f39c12;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.2);
}

.banner-text .subtitle {
    font-size: 1.1rem;
    margin-bottom: 30px;
    color: #e0e0e0;
    max-width: 600px;
}

.stats {
    display: flex;
    flex-wrap: wrap;
    gap: 30px;
    margin-top: 20px;
}

.stat-item {
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.stat-item .number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: #f39c12;
    margin-bottom: 5px;
}

.stat-item .label {
    font-size: 0.9rem;
    color: #b0c4de;
}


.breadcrumb {
    background-color: #f5f5f5;
    padding: 12px 0;
    border-bottom: 1px solid #e0e0e0;
}

.breadcrumb .container {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 8px;
}

.breadcrumb span,
.breadcrumb a {
    font-size: 0.9rem;
    color: #666;
}

.breadcrumb a {
    text-decoration: none;
    transition: color 0.2s;
}

.breadcrumb a:hover {
    color: #3498db;
}

.breadcrumb .current {
    color: #2c3e50;
    font-weight: 600;
}

.breadcrumb i {
    font-size: 0.8rem;
    color: #999;
}


.main-content {
    display: flex;
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    gap: 30px;
    position: relative; 
}


.sidebar {
    flex: 0 0 280px;
    background-color: #fff;
    border-radius: 6px;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.08);
    overflow: hidden;
    position: sticky; 
    top: 20px; 
    height: auto; 
    overflow-y: visible; 
    z-index: 100;
    
    -ms-overflow-style: none; 
    scrollbar-width: none; 
}


.sidebar::-webkit-scrollbar {
    display: none;
}






.product-categories {
    padding: 15px 0;
}

.category-list {
    list-style: none;
}

.category-item {
    border-bottom: 1px solid #f0f0f0;
}

.category-item:last-child {
    border-bottom: none;
}

.category-link {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 15px 20px;
    color: #2c3e50;
    text-decoration: none;
    font-size: 1rem;
    font-weight: 500;
    transition: all 0.3s ease;
    background-color: #f9f9f9;
    position: relative;
    cursor: pointer; 
}

.category-link:hover {
    background-color: #f0f7ff;
    color: #3498db;
    padding-left: 25px;
}

.category-link i {
    color: #7f8c8d;
    width: 20px;
    text-align: center;
    font-size: 1.1rem;
}

.category-item.active .category-link {
    background-color: #e8f4fc;
    color: #3498db;
    border-left: 4px solid #3498db;
    padding-left: 16px; 
    font-weight: 600;
}

.category-item.active .category-link i {
    color: #3498db;
}


.subcategory-list {
    list-style: none;
    background-color: #fff;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease-out;
}

.category-item.active .subcategory-list {
    max-height: 1000px; 
}

.subcategory-item {
    border-top: 1px solid #f5f5f5;
}

.subcategory-item a {
    display: block;
    padding: 12px 20px 12px 52px; 
    color: #666;
    text-decoration: none;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    position: relative;
}

.subcategory-item a:hover {
    background-color: #f5f9ff;
    color: #3498db;
    padding-left: 55px;
}

.subcategory-item a.active {
    background-color: #f5f9ff; 
    color: #2980b9; 
    font-weight: 600; 
    padding-left: 55px; 
}

.subcategory-item a::before {
    content: '·';
    position: absolute;
    left: 35px;
    top: 50%;
    transform: translateY(-50%);
    color: #bdc3c7;
    font-size: 1.2rem;
}

.subcategory-item a:hover::before {
    color: #3498db;
}
















.content-area {
    flex: 1;
    background-color: #fff;
    border-radius: 6px;
    padding: 30px;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.05);
    min-height: 1000px; 
    overflow-y: auto; 
}

.content-placeholder h2 {
    font-size: 1.6rem;
    color: #2c3e50;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #3498db;
}

.content-placeholder p {
    margin-bottom: 15px;
    line-height: 1.6;
    color: #555;
}


@media (max-width: 1024px) {
    .main-content {
        flex-direction: column;
    }
    
    .sidebar {
        flex: none;
        width: 100%;
        position: static; 
    }
    
    .stats {
        justify-content: center;
    }
    
    .stat-item {
        flex: 0 0 calc(25% - 30px);
    }
}

@media (max-width: 768px) {
    .promo-banner {
        padding: 30px 0;
    }
    
    .banner-text h1 {
        font-size: 1.8rem;
    }
    
    .stat-item {
        flex: 0 0 calc(50% - 15px);
    }
    
    .stat-item .number {
        font-size: 1.6rem;
    }
    
    .main-content {
        padding: 15px;
        gap: 20px;
    }
    
    .content-area {
        padding: 20px;
    }
}


.qrcode-section {
    text-align: center;
    padding: 20px;
    border-top: 1px solid #f0f0f0;
}

.qrcode-image {
    width: 120px;
    height: 120px;
    border-radius: 8px;
    margin-bottom: 10px;
}

.qrcode-text {
    font-size: 2rem;
    color: #666;
}