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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: #f5f5f5;
    color: #333;
}

/* 导航栏 */
.navbar {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 15px 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.navbar .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.navbar .logo {
    font-size: 24px;
    font-weight: bold;
    text-decoration: none;
    color: white;
}

.navbar .nav-links {
    display: flex;
    gap: 20px;
    align-items: center;
}

.navbar .nav-links a {
    color: white;
    text-decoration: none;
    padding: 8px 15px;
    border-radius: 5px;
    transition: background 0.3s;
}

.navbar .nav-links a:hover {
    background: rgba(255,255,255,0.2);
}

/* 容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* 轮播图 */
.banner-slider {
    width: 100%;
    height: 400px;
    position: relative;
    overflow: hidden;
    border-radius: 10px;
    margin-bottom: 30px;
}

.banner-slide {
    display: none;
    width: 100%;
    height: 100%;
}

.banner-slide.active {
    display: block;
}

.banner-slide img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* 公告 */
.announcement {
    background: #fff3cd;
    border: 1px solid #ffc107;
    padding: 15px;
    border-radius: 5px;
    margin-bottom: 30px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.announcement::before {
    content: '📢';
    font-size: 20px;
}

/* 分类 */
.categories {
    display: flex;
    gap: 15px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.category-btn {
    padding: 10px 20px;
    background: white;
    border: 2px solid #667eea;
    color: #667eea;
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    display: inline-block;
}

.category-btn:hover, .category-btn.active {
    background: #667eea;
    color: white;
}

/* 商品网格 */
.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.product-card {
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
    cursor: pointer;
}

.product-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(0,0,0,0.15);
}

.product-card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.product-info {
    padding: 15px;
}

.product-name {
    font-size: 16px;
    font-weight: bold;
    margin-bottom: 10px;
    color: #333;
}

.product-price {
    font-size: 20px;
    color: #e74c3c;
    font-weight: bold;
    margin-bottom: 10px;
}

.product-meta {
    display: flex;
    justify-content: space-between;
    font-size: 12px;
    color: #999;
    margin-bottom: 10px;
}

.add-to-cart-btn {
    width: 100%;
    padding: 10px;
    background: #667eea;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 14px;
    transition: background 0.3s;
}

.add-to-cart-btn:hover {
    background: #5568d3;
}

/* 按钮 */
.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s;
    text-decoration: none;
    display: inline-block;
}

.btn-primary {
    background: #667eea;
    color: white;
}

.btn-primary:hover {
    background: #5568d3;
}

.btn-danger {
    background: #e74c3c;
    color: white;
}

.btn-danger:hover {
    background: #c0392b;
}

.btn-success {
    background: #27ae60;
    color: white;
}

.btn-success:hover {
    background: #229954;
}

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

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
    color: #555;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 14px;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: #667eea;
}

/* 表格 */
table {
    width: 100%;
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

table th,
table td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid #eee;
}

table th {
    background: #667eea;
    color: white;
    font-weight: bold;
}

table tr:last-child td {
    border-bottom: none;
}

table tr:hover {
    background: #f8f9fa;
}

/* 页脚 */
.footer {
    background: #2c3e50;
    color: white;
    padding: 30px 0;
    margin-top: 50px;
    text-align: center;
}

.footer p {
    margin: 5px 0;
}

/* 消息提示 */
.alert {
    padding: 15px;
    border-radius: 5px;
    margin-bottom: 20px;
}

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

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

.alert-info {
    background: #d1ecf1;
    color: #0c5460;
    border: 1px solid #bee5eb;
}

/* 购物车徽章 */
.cart-badge {
    background: #e74c3c;
    color: white;
    border-radius: 50%;
    padding: 2px 6px;
    font-size: 12px;
    margin-left: 5px;
}

/* 响应式 */
@media (max-width: 768px) {
    .navbar .container {
        flex-direction: column;
        gap: 15px;
    }
    
    .products-grid {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
        gap: 10px;
    }
    
    .banner-slider {
        height: 200px;
    }
}