  <!-- 自定义样式 (SEO建议：CSS尽量外部引入或在此处精简) -->
    <style>
        :root {
            --primary-color: #0056b3; /* 品牌主色 */
            --secondary-color: #f8f9fa;
            --accent-color: #ffc107;
        }
        
        body {
            font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
            color: #333;
            line-height: 1.6; /* 增强可读性，利于SEO */
        }
 
        /* 导航栏样式 */
        .navbar-brand {
            font-weight: bold;
            font-size: 1.5rem;
        }
        .navbar-scrolled {
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
        }
 
 
		/* ========================================
		   index
		   ======================================== */
		 
 
        /* Hero 区域 */
        .hero-section {
            background: linear-gradient(135deg, #0061f2 0%, #00ba88 100%);
            color: white;
            padding: 100px 0;
            text-align: center;
        }
        .hero-section h1 {
            font-size: 3rem;
            font-weight: 700;
            margin-bottom: 20px;
        }
 
        /* 功能卡片 */
        .feature-card {
            border: none;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            height: 100%;
        }
        .feature-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 20px rgba(0,0,0,0.1);
        }
        .icon-box {
            font-size: 3rem;
            color: var(--primary-color);
            margin-bottom: 15px;
        }
 
        /* 数据统计区 */
        .stats-section {
            background-color: var(--secondary-color);
            padding: 60px 0;
        }
        .stat-item h2 {
            font-size: 2.5rem;
            font-weight: bold;
            color: var(--primary-color);
        }
 
        /* 页脚 */
        footer {
            background-color: #212529;
            color: white;
            padding: 50px 0 20px;
        }
        footer a {
            color: #adb5bd;
            text-decoration: none;
        }
        footer a:hover {
            color: white;
        }
		
		/* ========================================
		   category 
		   ======================================== */
		 .post-toc ul {
		     counter-reset: toc-counter;
		 }
		 
		 .post-toc li {
		     counter-increment: toc-counter;
		 }
		 
		 .post-toc li::before {
		     content: counter(toc-counter);
		     display: inline-block;
		     width: 1.2rem;
		     height: 1.2rem;
		     line-height: 1.2rem;
		     text-align: center;
		     background-color: var(--primary-color);
		     color: white;
		     border-radius: 50%;
		     font-size: 0.8rem;
		     margin-right: 0.5rem;
		 }
		 
		 /* 标签样式 */
		 .post-tags a {
		     display: inline-block;
		     padding: 0.3rem 0.8rem;
		     background-color: rgba(0,86,179,0.1);
		     color: var(--primary-color);
		     border-radius: 20px;
		     font-size: 0.9rem;
		     text-decoration: none;
		     margin-bottom: 0.5rem;
		 }
		 
		 .post-tags a:hover {
		     background-color: rgba(0,86,179,0.2);
		 }
		 
		 /* 阅读进度条 */
		 #reading-progress {
		     transition: width 0.3s ease;
		 }
		 
		 /* 移动端响应式优化 */
		 @media (max-width: 991.98px) {
		     .single-post .col-lg-8,
		     .single-post .col-lg-4 {
		         width: 100%;
		     }
		     
		     .post-content {
		         font-size: 1rem;
		     }
		 }

 
      
		
		/* ========================================
		   signle
		   ======================================== */
		 
		
		/* 文章详情页样式 */
		.single-post {
		    /* 页面基础样式 */
		}
		
		/* 文章内容样式优化 */
		.post-content {
		    font-size: 1.1rem;
		    line-height: 1.8;
		    color: #444;
		}
		
		.post-content h2,
		.post-content h3 {
		    color: var(--primary-color);
		    margin: 2rem 0 1rem;
		    font-weight: 600;
		}
		
		.post-content p {
		    margin-bottom: 1.5rem;
		}
		
		.post-content img {
		    max-width: 100%;
		    height: auto;
		    margin: 1.5rem 0;
		}
		
		.post-content blockquote {
		    border-left: 4px solid var(--primary-color);
		    padding-left: 1.5rem;
		    margin: 2rem 0;
		    font-style: italic;
		    color: #666;
		}
		
		/* 文章目录样式 */
		.post-toc ul {
		    counter-reset: toc-counter;
		}
		
		.post-toc li {
		    counter-increment: toc-counter;
		}
		
		.post-toc li::before {
		    content: counter(toc-counter);
		    display: inline-block;
		    width: 1.2rem;
		    height: 1.2rem;
		    line-height: 1.2rem;
		    text-align: center;
		    background-color: var(--primary-color);
		    color: white;
		    border-radius: 50%;
		    font-size: 0.8rem;
		    margin-right: 0.5rem;
		}
		
		/* 标签样式 */
		.post-tags a {
		    display: inline-block;
		    padding: 0.3rem 0.8rem;
		    background-color: rgba(0,86,179,0.1);
		    color: var(--primary-color);
		    border-radius: 20px;
		    font-size: 0.9rem;
		    text-decoration: none;
		    margin-bottom: 0.5rem;
		}
		
		.post-tags a:hover {
		    background-color: rgba(0,86,179,0.2);
		}
		
		/* 阅读进度条 */
		#reading-progress {
		    transition: width 0.3s ease;
		}
		
		/* 移动端响应式优化 */
		@media (max-width: 991.98px) {
		    .single-post .col-lg-8,
		    .single-post .col-lg-4 {
		        width: 100%;
		    }
		    
		    .post-content {
		        font-size: 1rem;
		    }
		}
		
		/* ========================================
		   404页面SEO优化样式表
		   基于Bootstrap 5.x扩展 
		   ======================================== */
		 
		/* 1. 核心容器 - 确保内容居中且响应式 */
		.error-container {
		    min-height: 60vh;
		    display: flex;
		    align-items: center;
		    padding: 60px 0;
		    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
		}
		 
		/* 2. 错误代码样式 - 视觉冲击力 */
		.error-code {
		    font-size: clamp(120px, 20vw, 200px);
		    font-weight: 700;
		    color: #dee2e6;
		    line-height: 1;
		    margin-bottom: 20px;
		    text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
		    /* SEO: 语义化大标题，便于搜索引擎理解页面类型 */
		}
		 
		/* 3. 标题样式 - H1标签优化 */
		.error-title {
		    font-size: clamp(28px, 5vw, 42px);
		    font-weight: 600;
		    color: #212529;
		    margin-bottom: 16px;
		    /* SEO: 清晰的H1标签，包含关键词"页面" */
		}
		 
		/* 4. 描述文本 - 内容可读性 */
		.error-description {
		    font-size: 18px;
		    color: #6c757d;
		    max-width: 500px;
		    margin: 0 auto 30px;
		    line-height: 1.6;
		    /* SEO: 提供有价值的文本内容，降低跳出率 */
		}
		 
		/* 5. 搜索框样式 - 引导用户继续浏览 */
		.search-box {
		    max-width: 450px;
		    margin: 0 auto 30px;
		}
		 
		.search-box .search-field {
		    width: 100%;
		    padding: 12px 20px;
		    border: 2px solid #dee2e6;
		    border-radius: 30px;
		    font-size: 16px;
		    transition: all 0.3s ease;
		}
		 
		.search-box .search-field:focus {
		    border-color: #0d6efd;
		    box-shadow: 0 0 0 3px rgba(13, 110, 253, 0.15);
		    outline: none;
		}
		 
		/* 6. 操作按钮 - 内链建设 */
		.action-buttons {
		    display: flex;
		    gap: 15px;
		    justify-content: center;
		    flex-wrap: wrap;
		    margin-bottom: 50px;
		}
		 
		.action-buttons .btn {
		    padding: 12px 30px;
		    font-size: 16px;
		    font-weight: 500;
		    border-radius: 30px;
		    transition: all 0.3s ease;
		}
		 
		.action-buttons .btn-primary {
		    background: #0d6efd;
		    border: none;
		}
		 
		.action-buttons .btn-primary:hover {
		    background: #0b5ed7;
		    transform: translateY(-2px);
		    box-shadow: 0 4px 12px rgba(13, 110, 253, 0.3);
		}
		 
		/* 7. 推荐文章区域 - 增加页面停留时间 */
		.recommended-posts {
		    padding-top: 40px;
		    border-top: 1px solid #dee2e6;
		}
		 
		.recommended-posts h3 {
		    font-size: 20px;
		    color: #495057;
		    margin-bottom: 20px;
		}
		 
		.recommended-item {
		    display: block;
		    padding: 10px 15px;
		    margin-bottom: 8px;
		    background: #fff;
		    border-radius: 8px;
		    color: #495057;
		    text-decoration: none;
		    transition: all 0.2s ease;
		}
		 
		.recommended-item:hover {
		    background: #f8f9fa;
		    color: #0d6efd;
		    padding-left: 20px;
		}
		 
		/* 8. 响应式适配 */
		@media (max-width: 768px) {
		    .error-container {
		        padding: 40px 0;
		    }
		    
		    .error-description {
		        font-size: 16px;
		    }
		    
		    .action-buttons .btn {
		        padding: 10px 24px;
		        font-size: 14px;
		    }
		}
		 
		/* 9. SEO隐藏文本 - 屏幕阅读器可见 */
		.seo-hidden-text {
		    position: absolute;
		    width: 1px;
		    height: 1px;
		    padding: 0;
		    margin: -1px;
		    overflow: hidden;
		    clip: rect(0, 0, 0, 0);
		    white-space: nowrap;
		    border: 0;
		}
		 
		/* 10. 结构化数据标记辅助 */
		.error-schema {
		    display: none;
		}
    </style>