* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
        }
        
        body {
            background-color: #f5f7fa;
            color: #333;
            line-height: 1.6;
        }
        
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        
        /* 页面头部 */
        .page-header {
            background: linear-gradient(135deg, #4a6ee0 0%, #6b8ce6 100%);
            color: white;
            padding: 40px 0;
            margin-bottom: 30px;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
        }
        
        .header-content {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .page-title {
            font-size: 2.2rem;
            font-weight: 600;
            margin-bottom: 5px;
        }
        
        .breadcrumb {
            font-size: 0.95rem;
            opacity: 0.9;
        }
        
        .breadcrumb a {
            color: white;
            text-decoration: none;
        }
        
        .breadcrumb a:hover {
            text-decoration: underline;
        }
        
        /* 筛选栏 */
        .filters {
            background: white;
            border-radius: 10px;
            padding: 20px;
            margin-bottom: 25px;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
        }
        
        .filter-group {
            display: flex;
            align-items: center;
            flex-wrap: wrap;
            gap: 15px;
        }
        
        .filter-label {
            font-weight: 600;
            color: #555;
        }
        
        .filter-select {
            padding: 8px 15px;
            border: 1px solid #ddd;
            border-radius: 6px;
            background: white;
            font-size: 0.95rem;
            cursor: pointer;
            transition: all 0.3s;
        }
        
        .filter-select:focus {
            border-color: #4a6ee0;
            outline: none;
            box-shadow: 0 0 0 2px rgba(74, 110, 224, 0.2);
        }
        
        .search-box {
            position: relative;
            flex-grow: 1;
            max-width: 300px;
        }
        
        .search-icon {
            position: absolute;
            left: 12px;
            top: 50%;
            transform: translateY(-50%);
            color: #888;
        }
        
        .search-input {
            width: 100%;
            padding: 8px 15px 8px 40px;
            border: 1px solid #ddd;
            border-radius: 6px;
            font-size: 0.95rem;
            transition: all 0.3s;
        }
        
        .search-input:focus {
            border-color: #4a6ee0;
            outline: none;
            box-shadow: 0 0 0 2px rgba(74, 110, 224, 0.2);
        }
        
        /* 列表容器 */
        .list-container {
            background: white;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
            margin-bottom: 30px;
        }
        
        .list-header {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1fr;
            gap: 15px;
            padding: 15px 20px;
            background: #f8f9fa;
            font-weight: 600;
            color: #555;
            border-bottom: 1px solid #eee;
        }
        
        .knowledge-list {
            list-style: none;
        }
        
        .knowledge-item {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1fr;
            gap: 15px;
            padding: 18px 20px;
            border-bottom: 1px solid #f0f0f0;
            transition: background 0.3s;
        }
        
        .knowledge-item:hover {
            background: #f8fafd;
        }
        
        .item-title a {
            color: #333;
            text-decoration: none;
            font-weight: 500;
            transition: color 0.3s;
        }
        
        .item-title a:hover {
            color: #4a6ee0;
        }
        
        .subject-tag {
            display: inline-block;
            padding: 4px 10px;
            border-radius: 20px;
            font-size: 0.85rem;
            font-weight: 500;
        }
        
        .subject-数学 {
            background: #e3f2fd;
            color: #1976d2;
        }
        
        .subject-语文 {
            background: #f3e5f5;
            color: #7b1fa2;
        }
        
        .subject-英语 {
            background: #e8f5e9;
            color: #388e3c;
        }
        
        .subject-物理 {
            background: #fff3e0;
            color: #f57c00;
        }
        
        .subject-化学 {
            background: #e0f2f1;
            color: #00796b;
        }
        
        .subject-生物 {
            background: #fce4ec;
            color: #c2185b;
        }
        
        .difficulty {
            display: flex;
            align-items: center;
            gap: 8px;
        }
        
        .difficulty i {
            color: #888;
        }
        
        .difficulty-基础 i {
            color: #4caf50;
        }
        
        .difficulty-中等 i {
            color: #ff9800;
        }
        
        .difficulty-进阶 i {
            color: #f44336;
        }
        
        .date {
            color: #777;
            font-size: 0.9rem;
        }
        
        /* 空状态 */
        .empty-state {
            text-align: center;
            padding: 60px 20px;
            color: #888;
        }
        
        .empty-state i {
            font-size: 3rem;
            margin-bottom: 15px;
            color: #ccc;
        }
        
        .empty-state h3 {
            font-size: 1.5rem;
            margin-bottom: 10px;
            color: #666;
        }
        
        /* 分页 */
        .pagination {
            display: flex;
            justify-content: center;
            margin-bottom: 40px;
        }
        
.pagination span {
           /* display: inline-block;*/
            padding: 8px 15px;
            margin: 0 4px;
            border-radius: 5px;
            text-decoration: none;
            color: #555;
            transition: all 0.3s;
        }
		        .pagination a {
           /* display: inline-block;*/
            padding: 8px 15px;
            margin: 0 4px;
            border-radius: 5px;
            border: 1px solid #ddd;
            text-decoration: none;
            color: #555;
            transition: all 0.3s;
        }
        
        .pagination a:hover {
            background: #4a6ee0;
            color: white;
            border-color: #4a6ee0;
        }
        
        .pagination .current {
            background: #4a6ee0;
            color: white;
            border-color: #4a6ee0;
        }
        
        /* 响应式设计 */
        @media (max-width: 768px) {
            .header-content {
                flex-direction: column;
                align-items: flex-start;
            }
            
            .breadcrumb {
                margin-top: 10px;
            }
            
            .filter-group {
                flex-direction: column;
                align-items: flex-start;
            }
            
            .search-box {
                max-width: 100%;
                width: 100%;
            }
            
            .list-header, .knowledge-item {
                grid-template-columns: 1fr;
                gap: 10px;
            }
            
            .list-header div:nth-child(2),
            .list-header div:nth-child(3),
            .list-header div:nth-child(4) {
                display: none;
            }
            
            .knowledge-item > div:nth-child(2),
            .knowledge-item > div:nth-child(3),
            .knowledge-item > div:nth-child(4) {
                display: flex;
                align-items: center;
                gap: 8px;
            }
            
            .knowledge-item > div:nth-child(2)::before {
                content: "学科:";
                font-weight: 600;
                color: #666;
            }
            
            .knowledge-item > div:nth-child(3)::before {
                content: "难度:";
                font-weight: 600;
                color: #666;
            }
            
            .knowledge-item > div:nth-child(4)::before {
                content: "更新:";
                font-weight: 600;
                color: #666;
            }
        }
		
/*详情页*/

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        body {
            background: #f8fafc;
            color: #334155;
            font-family: 'Inter', sans-serif;
            line-height: 1.6;
        }
        
        .container {
            max-width: 1400px;
            margin: 0 auto;
            padding: 0 20px;
        }
        
        /* 头部样式 */
        .page-header {
            background: white;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
            padding: 20px 0;
            margin-bottom: 30px;
        }
        
        .header-content {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .breadcrumb {
            color: #64748b;
            font-size: 0.9rem;
        }
        
        .breadcrumb a {
            color: #3b82f6;
            text-decoration: none;
        }
        
        .breadcrumb a:hover {
            text-decoration: underline;
        }
        
        /* 主要内容区域 */
        .content-main {
            display: grid;
            grid-template-columns: 1fr 300px;
            gap: 30px;
        }
        
        @media (max-width: 768px) {
            .content-main {
                grid-template-columns: 1fr;
            }
        }
        
        /* 文章内容 */
        .article-card {
            background: white;
            border-radius: 12px;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
            overflow: hidden;
            margin-bottom: 30px;
        }
        
        .article-header {
            padding: 30px;
            border-bottom: 1px solid #f1f5f9;
        }
        
        .article-meta {
            display: flex;
            flex-wrap: wrap;
            gap: 15px;
            margin-bottom: 15px;
        }
        
        .subject-tag {
            display: inline-block;
            padding: 6px 12px;
            border-radius: 20px;
            font-size: 0.85rem;
            font-weight: 600;
        }
        
        .math .subject-tag {
            background: #fef2f2;
            color: #dc2626;
        }
        
        .difficulty {
            display: flex;
            align-items: center;
            gap: 5px;
            font-size: 0.85rem;
            color: #64748b;
        }
        
        .date {
            color: #94a3b8;
            font-size: 0.85rem;
        }
        
        .article-title {
            font-size: 1.8rem;
            font-weight: 700;
            color: #1e293b;
            line-height: 1.3;
            margin-bottom: 10px;
        }
        
        .article-description {    color: #c7c7d5;
    font-size: 1rem;
    line-height: 2.2;
    letter-spacing: 2px;
        }
        
        .article-content {
            padding: 30px;
            font-family: 'Noto Serif SC', serif;
        }
        
        .article-content h2 {
            font-size: 1.5rem;
            font-weight: 600;
            color: #1e293b;
            margin: 30px 0 15px;
            padding-bottom: 8px;
            border-bottom: 1px solid #e2e8f0;
        }
        
        .article-content h3 {
            font-size: 1.3rem;
            font-weight: 600;
            color: #1e293b;
            margin: 25px 0 12px;
        }
        
        .article-content p {
            margin-bottom: 16px;
            color: #475569;
            line-height: 1.7;
        }
        
        .article-content ul, .article-content ol {
            margin-bottom: 16px;
            padding-left: 24px;
        }
        
        .article-content li {
            margin-bottom: 8px;
            color: #475569;
        }
        
        .example-box {
            background: #f8fafc;
            border-left: 4px solid #3b82f6;
            padding: 20px;
            margin: 20px 0;
            border-radius: 0 8px 8px 0;
        }
        
        .example-title {
            font-weight: 600;
            color: #1e40af;
            margin-bottom: 10px;
            display: flex;
            align-items: center;
            gap: 8px;
        }
        
        .formula {
            background: #f1f5f9;
            padding: 15px;
            border-radius: 8px;
            margin: 15px 0;
            font-family: 'Inter', monospace;
            overflow-x: auto;
        }
        
        .formula-title {
            font-weight: 600;
            color: #475569;
            margin-bottom: 8px;
            font-size: 0.9rem;
        }
        
        .key-point {
            background: #fff7ed;
            border-left: 4px solid #f59e0b;
            padding: 20px;
            margin: 20px 0;
            border-radius: 0 8px 8px 0;
        }
        
        .key-point-title {
            font-weight: 600;
            color: #92400e;
            margin-bottom: 10px;
            display: flex;
            align-items: center;
            gap: 8px;
        }
        
        /* 侧边栏 */
        .sidebar {
            display: flex;
            flex-direction: column;
            gap: 20px;
        }
        
        .sidebar-card {
            background: white;
            border-radius: 12px;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
            overflow: hidden;
        }
        
        .sidebar-header {
            padding: 15px 20px;
            background: #f8fafc;
            border-bottom: 1px solid #e2e8f0;
            font-weight: 600;
            color: #475569;
        }
        
        .sidebar-content {
            padding: 20px;
        }
        
        .nav-links {
            list-style: none;
        }
        
        .nav-links li {
            margin-bottom: 12px;
        }
        
        .nav-links a {
            display: flex;
            align-items: center;
            gap: 10px;
            color: #475569;
            text-decoration: none;
            transition: color 0.2s;
        }
        
        .nav-links a:hover {
            color: #3b82f6;
        }
        
        .nav-links i {
            color: #94a3b8;
            width: 16px;
        }
        
        .related-list {
            list-style: none;
        }
        
        .related-item {
            margin-bottom: 15px;
            padding-bottom: 15px;
            border-bottom: 1px solid #f1f5f9;
        }
        
        .related-item:last-child {
            margin-bottom: 0;
            padding-bottom: 0;
            border-bottom: none;
        }
        
        .related-item a {
            color: #475569;
            text-decoration: none;
            font-weight: 500;
            display: block;
            margin-bottom: 5px;
            transition: color 0.2s;
        }
        
        .related-item a:hover {
            color: #3b82f6;
        }
        
        .related-meta {
            display: flex;
            gap: 10px;
            font-size: 0.8rem;
            color: #94a3b8;
        }
        
        /* 文章底部 */
        .article-footer {
            display: flex;
            justify-content: space-between;
            padding: 20px 30px;
            background: #f8fafc;
            border-top: 1px solid #e2e8f0;
        }
        
        .action-buttons {
            display: flex;
            gap: 15px;
        }
        
        .btn {
            display: flex;
            align-items: center;
            gap: 6px;
            padding: 8px 16px;
            border-radius: 6px;
            font-size: 0.9rem;
            font-weight: 500;
            cursor: pointer;
            transition: all 0.2s;
            text-decoration: none;
        }
        
        .btn-primary {
            background: #3b82f6;
            color: white;
            border: none;
        }
        
        .btn-primary:hover {
            background: #2563eb;
        }
        
        .btn-outline {
            background: white;
            color: #475569;
            border: 1px solid #cbd5e1;
        }
        
        .btn-outline:hover {
            background: #f8fafc;
            border-color: #94a3b8;
        }
        
        /* 响应式设计 */
        @media (max-width: 768px) {
            .article-header, .article-content {
                padding: 20px;
            }
            
            .article-title {
                font-size: 1.5rem;
            }
            
            .article-meta {
                flex-direction: column;
                gap: 10px;
            }
            
            .article-footer {
                flex-direction: column;
                gap: 15px;
            }
        }