* { 
            margin: 0; 
            padding: 0; 
            box-sizing: border-box; 
        }
        
        body { 
            font-family: 'Noto Sans SC', 'Roboto', sans-serif; 
            line-height: 1.6; 
            color: #333; 
            background: #f8f9fa;
        }
        
        .document-wrapper {
            display: flex;
            min-height: 100vh;
            max-width: 1600px;
            margin: 0 auto;
            padding: 20px;
            gap: 20px;
        }
        
        /* 左侧目录栏 */
        .sidebar {
            width: 300px;
            background: white;
            border-radius: 12px;
            box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
            padding: 25px;
            position: sticky;
            top: 20px;
            height: fit-content;
            max-height: calc(100vh - 40px);
            overflow-y: auto;
        }
        
        .sidebar-header {
            margin-bottom: 20px;
            padding-bottom: 15px;
            border-bottom: 2px solid #e9ecef;
        }
        
        .sidebar-header h2 {
            color: #2c3e50;
            font-size: 1.4rem;
            font-weight: 600;
        }
        
        .sidebar-header p {
            color: #6c757d;
            font-size: 0.9rem;
            margin-top: 5px;
        }
        
        .toc-list {
            list-style: none;
        }
        
        .toc-item {
            margin-bottom: 8px;
        }
        
        .toc-link {
            display: block;
            padding: 12px 15px;
            color: #495057;
            text-decoration: none;
            border-radius: 8px;
            transition: all 0.3s ease;
            font-weight: 500;
            border-left: 3px solid transparent;
        }
        
        .toc-link:hover {
            background-color: #f1f3f4;
            color: #2c3e50;
            border-left-color: #4a6cf7;
        }
        
        .toc-link.active {
            background-color: #e7f0ff;
            color: #4a6cf7;
            border-left-color: #4a6cf7;
        }
        
        .toc-subitem {
            margin-left: 20px;
            margin-top: 5px;
        }
        
        /* 右侧内容区 */
        .content-area {
            flex: 1;
            background: white;
            border-radius: 12px;
            box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
            padding: 30px;
            overflow-y: auto;
        }
        
        .document-header {
            margin-bottom: 30px;
            padding-bottom: 20px;
            border-bottom: 1px solid #e9ecef;
        }
        
        .document-header h1 {
            color: #2c3e50;
            font-size: 2.2rem;
            font-weight: 700;
            margin-bottom: 10px;
        }
        
        .document-header p {
            color: #6c757d;
            font-size: 1.1rem;
            line-height: 1.7;
        }
        
        .meta {
            display: flex;
            gap: 25px;
            color: #6c757d;
            font-size: 0.9rem;
            margin-top: 15px;
            flex-wrap: wrap;
        }
        
        .meta span {
            display: flex;
            align-items: center;
            gap: 5px;
        }
        
        .meta i {
            color: #4a6cf7;
        }
        
        .sections-container {
            margin-top: 20px;
        }
        
        .section {
            margin-bottom: 40px;
            padding-bottom: 30px;
            border-bottom: 1px solid #e9ecef;
        }
        
        .section:last-child {
            border-bottom: none;
        }
        
        .section h2 {
            color: #2c3e50;
            font-size: 1.8rem;
            font-weight: 600;
            margin-bottom: 15px;
            padding-bottom: 10px;
            border-bottom: 2px solid #f1f3f4;
        }
        
        .section-description {
            color: #6c757d;
            font-style: italic;
            margin-bottom: 20px;
            padding-left: 15px;
            border-left: 3px solid #e9ecef;
        }
        
        .section-content {
            margin-top: 20px;
        }
        
        .content-item {
            margin-bottom: 20px;
        }
        
        .content-item p {
            line-height: 1.8;
            color: #444;
            font-size: 1.05rem;
        }
        
        .image-container {
            margin: 20px 0;
            text-align: center;
        }
        
        .image-container img {
            max-width: 100%;
            border-radius: 8px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
        }
        
        .image-caption {
            text-align: center;
            color: #6c757d;
            font-size: 0.9rem;
            margin-top: 8px;
            font-style: italic;
        }
        
        .video-container {
            margin: 20px 0;
        }
        
        .video-container video {
            width: 100%;
            border-radius: 8px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
        }
        
        .video-caption {
            text-align: center;
            color: #6c757d;
            font-size: 0.9rem;
            margin-top: 8px;
            font-style: italic;
        }
        
        pre {
            background: #2d3748;
            color: #e2e8f0;
            padding: 20px;
            border-radius: 8px;
            overflow-x: auto;
            font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
            font-size: 0.95rem;
            line-height: 1.5;
            margin: 20px 0;
        }
        
        code {
            font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
        }
        
        .section-meta {
            color: #6c757d;
            font-size: 0.9rem;
            margin-top: 20px;
            padding-top: 15px;
            border-top: 1px dashed #e9ecef;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .loading {
            text-align: center;
            padding: 60px 20px;
            color: #6c757d;
            font-size: 1.1rem;
        }
        
        .loading:after {
            content: '...';
            animation: dots 1.5s steps(4, end) infinite;
        }
        
        @keyframes dots {
            0%, 20% { content: '.'; }
            40% { content: '..'; }
            60%, 100% { content: '...'; }
        }
        
        .empty-state {
            text-align: center;
            padding: 60px 20px;
            color: #6c757d;
        }
        
        .empty-state h3 {
            color: #2c3e50;
            margin-bottom: 10px;
        }
        
        .empty-state a {
            color: #4a6cf7;
            text-decoration: none;
        }
        
        /* 响应式设计 */
        @media (max-width: 992px) {
            .document-wrapper {
                flex-direction: column;
                padding: 15px;
            }
            
            .sidebar {
                width: 100%;
                position: static;
                max-height: none;
            }
            
            .content-area {
                padding: 20px;
            }
        }
        
        @media (max-width: 768px) {
            .meta {
                flex-direction: column;
                gap: 10px;
            }
            
            .document-header h1 {
                font-size: 1.8rem;
            }
            
            .section h2 {
                font-size: 1.5rem;
            }
        }
        
        /* 滚动条样式 */
        .sidebar::-webkit-scrollbar {
            width: 6px;
        }
        
        .sidebar::-webkit-scrollbar-track {
            background: #f1f1f1;
            border-radius: 3px;
        }
        
        .sidebar::-webkit-scrollbar-thumb {
            background: #c1c1c1;
            border-radius: 3px;
        }
        
        .sidebar::-webkit-scrollbar-thumb:hover {
            background: #a8a8a8;
        }
        
        /* 高亮当前阅读位置 */
        .section-highlight {
            background-color: #f8f9ff;
            border-left: 4px solid #4a6cf7;
            padding-left: 20px;
            transition: all 0.3s ease;
        }