:root {
            --primary: #00BEBD;
            --dark: #1e293b;
            --text: #334155;
            --gray: #94a3b8;
            --bg: #FFFFFF;
            --section-bg: #F8FAFC;
        }

        * { margin: 0; padding: 0; box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
        body { background: var(--bg); font-family: -apple-system, "PingFang SC", sans-serif; color: var(--text); line-height: 1.8; }
        
        /* 1. 阅读进度条 */
        .progress-bar {
            position: fixed; top: 0; left: 0; width: 0%; height: 3px;
            background: var(--primary); z-index: 1001; transition: width 0.1s;
        }

        .container { width: 100%; max-width: 800px; margin: 0 auto; padding: 0 20px; }

        /* 2. 文章头部 */
        .article-header { padding: 30px 0 20px; border-bottom: 1px solid #F1F5F9; margin-bottom: 30px; }
        .breadcrumb { font-size: 0.8rem; color: var(--gray); margin-bottom: 15px; }
        .breadcrumb a { color: var(--gray); text-decoration: none; }
        .article-title { font-size: 1.6rem; line-height: 1.4; color: var(--dark); margin-bottom: 15px; font-weight: 800; }
        .article-meta { display: flex; align-items: center; gap: 15px; font-size: 0.85rem; color: var(--gray); }

        /* 3. 自动目录 (移动端隐藏，PC端显示) */
        .article-content { position: relative; }
        
        /* 4. 正文排版优化 (关键：针对SEO和可读性) */
        .post-body { font-size: 1.05rem; color: #374151; }
        .post-body h2 { 
            font-size: 1.3rem; color: var(--dark); margin: 35px 0 15px; 
            padding-left: 12px; border-left: 4px solid var(--primary); background: var(--section-bg); padding: 8px 12px;
        }
        .post-body p { margin-bottom: 20px; text-align: justify; }
        .post-body img { width: 100%; border-radius: 12px; margin: 10px 0 25px; box-shadow: 0 4px 15px rgba(0,0,0,0.05); }
        .post-body strong { color: var(--dark); }
        
        /* 重点强调框 */
        .info-box { 
            background: rgba(0, 190, 189, 0.05); border: 1px dashed var(--primary); 
            padding: 20px; border-radius: 12px; margin: 25px 0; position: relative;
        }
        .info-box::after { content: "💡 提示"; position: absolute; top: -12px; left: 20px; background: var(--primary); color: #fff; font-size: 0.75rem; padding: 2px 10px; border-radius: 4px; }

        /* 5. 文末领队卡片 */
        .author-card {
            margin: 50px 0; padding: 25px; background: var(--section-bg); 
            border-radius: 16px; display: flex; align-items: center; gap: 20px;
        }
        .author-avatar { width: 60px; height: 60px; border-radius: 50%; border: 2px solid #fff; }
        .author-info h4 { font-size: 1.1rem; margin-bottom: 5px; color: var(--dark); }
        .author-info p { font-size: 0.85rem; color: var(--gray); line-height: 1.4; }
        .add-btn { 
            margin-left: auto; background: var(--primary); color: #fff; 
            padding: 8px 18px; border-radius: 20px; font-size: 0.85rem; font-weight: bold; text-decoration: none;
        }

        /* 6. 相关阅读 */
        .related-posts { border-top: 1px solid #F1F5F9; padding-top: 30px; margin-bottom: 50px; }
        .related-posts h3 { font-size: 1.1rem; margin-bottom: 20px; }
        .related-list { list-style: none; }
        .related-list li { margin-bottom: 12px; }
        .related-list a { color: var(--primary); text-decoration: none; font-size: 0.95rem; display: block; }
        .related-list a:hover { text-decoration: underline; }


/* --- 新增：头部导航 --- */
        .site-header {
            background: #fff; height: 60px; display: flex; align-items: center;
            padding: 0 20px; border-bottom: 1px solid #f1f5f9; position: sticky; top: 0; z-index: 1000;
        }
        .logo { font-size: 1.2rem; font-weight: 800; color: var(--primary); text-decoration: none; }
        
        /* --- 新增：上下分页 --- */
        .article-nav {
            display: flex; justify-content: space-between; gap: 15px; margin: 40px 0;
        }
        .nav-btn {
            flex: 1; padding: 15px; background: #f8fafc; border-radius: 12px;
            text-decoration: none; display: flex; flex-direction: column; gap: 5px;
            border: 1px solid #e2e8f0; transition: 0.3s;
        }
        .nav-btn:hover { border-color: var(--primary); background: #fff; }
        .nav-label { font-size: 0.75rem; color: var(--gray); }
        .nav-title { font-size: 0.9rem; color: var(--dark); font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

        /* --- 新增：版权底部 --- */
        .site-footer {
            background: #1e293b; color: #94a3b8; padding: 40px 20px 100px;
            text-align: center; font-size: 0.85rem; margin-top: 50px;
        }
        .footer-links { display: flex; justify-content: center; gap: 20px; margin-bottom: 15px; }
        .footer-links a { color: #cbd5e1; text-decoration: none; }
        .copyright { opacity: 0.7; }


        /* 移动端适配 */
        @media (max-width: 768px) {
            .article-title { font-size: 1.4rem; }
            .author-card { flex-direction: column; text-align: center; }
            .add-btn { margin: 10px auto 0; }
        }