/* 全局样式 */
        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background-color: #f5f5f5;
            color: #333;
            line-height: 1.6;
        }
        
        /* 布局 */
        .container {
            display: flex;
            flex-wrap: wrap;
            max-width: 1200px;
            margin: 0 auto;
            padding: 20px;
        }
        
        .sidebar {
            flex: 1;
            min-width: 250px;
            padding: 20px;
            background-color: #fff;
            border-radius: 8px;
            box-shadow: 0 2px 5px rgba(0,0,0,0.1);
            margin-right: 20px;
            margin-bottom: 20px;
        }
        
        .main-content {
            flex: 3;
            min-width: 300px;
        }
        
        /* 分类样式 */
        .categories h2 {
            margin-bottom: 15px;
            color: #2c3e50;
            border-bottom: 2px solid #3498db;
            padding-bottom: 5px;
        }
        
        .category-list {
            list-style: none;
        }
        
        .category-item {
            margin-bottom: 10px;
        }
        
        .category-item a {
            text-decoration: none;
            color: #34495e;
            display: block;
            padding: 8px 10px;
            border-radius: 4px;
            transition: all 0.3s ease;
        }
        
        .category-item a:hover, .category-item a.active {
            background-color: #3498db;
            color: white;
        }
        
        /* 书籍卡片样式 */
        .book-card {
            background-color: #fff;
            border-radius: 8px;
            box-shadow: 0 2px 5px rgba(0,0,0,0.1);
            padding: 20px;
            margin-bottom: 20px;
        }
        
        .book-header {
            display: flex;
            justify-content: space-between;
            margin-bottom: 15px;
            border-bottom: 1px solid #eee;
            padding-bottom: 10px;
        }
        
        .book-title {
            font-size: 1.5rem;
            color: #2c3e50;
        }
        
        .book-meta {
            display: flex;
            font-size: 0.9rem;
            color: #7f8c8d;
        }
        
        .book-meta span {
            margin-right: 15px;
        }
        
        .book-meta i {
            margin-right: 5px;
        }
        
        .book-content {
            margin-bottom: 20px;
        }
        
        .book-image {
            float: left;
            width: 120px;
            margin-right: 20px;
            margin-bottom: 10px;
            border-radius: 4px;
        }
        
        /* 留言区样式 */
        .comments-section {
            margin-top: 20px;
            border-top: 1px solid #eee;
            padding-top: 15px;
        }
        
        .comments-title {
            font-size: 1.2rem;
            margin-bottom: 15px;
            color: #2c3e50;
        }
        
        .comment-form textarea {
            width: 100%;
            padding: 10px;
            border: 1px solid #ddd;
            border-radius: 4px;
            resize: vertical;
            min-height: 80px;
            margin-bottom: 10px;
        }
        
        .comment-form button {
            background-color: #3498db;
            color: white;
            border: none;
            padding: 8px 15px;
            border-radius: 4px;
            cursor: pointer;
            transition: background-color 0.3s;
        }
        
        .comment-form button:hover {
            background-color: #2980b9;
        }
        
        .comment-list {
            margin-top: 20px;
        }
        
        .comment {
            padding: 10px;
            background-color: #f9f9f9;
            border-radius: 4px;
            margin-bottom: 10px;
        }
        
        .comment-author {
            font-weight: bold;
            color: #2c3e50;
            margin-bottom: 5px;
        }
        
        .comment-date {
            font-size: 0.8rem;
            color: #7f8c8d;
            margin-bottom: 5px;
        }
        
        /* 响应式设计 */
        @media (max-width: 768px) {
            .sidebar {
                flex: 100%;
                margin-right: 0;
            }
            
            .main-content {
                flex: 100%;
            }
            
            .book-image {
                float: none;
                width: 100%;
                margin-right: 0;
                margin-bottom: 15px;
            }
        }