/* 全局核心样式 */
    :root { --primary: #3b82f6; --primary-hover: #2563eb; --bg: #f3f4f6; --text-main: #1f2937; --text-light: #6b7280; --card-bg: #ffffff; }
    body { font-family: -apple-system, "Microsoft YaHei", sans-serif; background: var(--bg); color: var(--text-main); margin: 0; line-height: 1.6; }
    a { text-decoration: none; color: inherit; transition: all 0.3s ease; }
    
    /* 顶部导航美化 */
    .header { background: var(--card-bg); box-shadow: 0 2px 10px rgba(0,0,0,0.05); position: sticky; top: 0; z-index: 100; }
    .nav-container { max-width: 1200px; margin: 0 auto; padding: 15px 20px; display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 15px; }
    .logo { font-size: 24px; font-weight: 800; color: var(--primary); letter-spacing: 1px; }
    .nav-links { display: flex; gap: 10px; flex-wrap: wrap; }
    .nav-links a { padding: 6px 16px; border-radius: 20px; font-size: 15px; font-weight: 500; background: #f3f4f6; color: var(--text-main); }
    .nav-links a:hover, .nav-links a.active { background: var(--primary); color: #fff; }

    /* 内容区排版 */
    .main-container { max-width: 1200px; margin: 30px auto; padding: 0 20px; }
    .section-title { font-size: 20px; font-weight: bold; border-left: 4px solid var(--primary); padding-left: 12px; margin-bottom: 20px; }
    
    /* 图片卡片网格 */
    .grid-cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 20px; margin-bottom: 40px; }
    .card { background: var(--card-bg); border-radius: 10px; overflow: hidden; box-shadow: 0 4px 6px rgba(0,0,0,0.02); transition: transform 0.3s; }
    .card:hover { transform: translateY(-5px); box-shadow: 0 10px 15px rgba(0,0,0,0.08); }
    .card-img { width: 100%; aspect-ratio: 3/4; object-fit: cover; display: block; }
    .card-info { padding: 15px; }
    .card-info h3 { font-size: 15px; margin: 0 0 8px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
    .card-meta { font-size: 12px; color: var(--text-light); display: flex; justify-content: space-between; }

    /* SEO 纯文本推荐矩阵 */
    .seo-text-matrix { background: var(--card-bg); padding: 25px; border-radius: 10px; margin-bottom: 40px; border-top: 3px solid var(--primary); }
    .matrix-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 20px; }
    .matrix-grid ul { list-style: none; padding: 0; margin: 0; }
    .matrix-grid li { margin-bottom: 12px; border-bottom: 1px dashed #e5e7eb; padding-bottom: 8px; font-size: 14px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
    .matrix-grid li a::before { content: "▪"; color: var(--primary); margin-right: 8px; }
    .matrix-grid li a:hover { color: var(--primary); }

    /* 正规化底部 Footer */
    .footer { background: #1f2937; color: #d1d5db; padding: 50px 20px 20px; font-size: 14px; }
    .footer-grid { max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 40px; margin-bottom: 30px; }
    .footer-col h4 { color: #fff; font-size: 16px; margin-bottom: 15px; }
    .footer-col p { margin: 0 0 10px; line-height: 1.8; }
    .footer-links { list-style: none; padding: 0; margin: 0; }
    .footer-links li { margin-bottom: 10px; }
    .footer-links a:hover { color: #fff; text-decoration: underline; }
    .footer-bottom { text-align: center; padding-top: 20px; border-top: 1px solid #374151; color: #9ca3af; }