:root {
      --primary: rgb(255, 45, 85);
      --primary-hover: rgb(230, 30, 70);
      --bg-dark: #111116;
      --bg-light: #f8f9fa;
      --text-dark: #1f2937;
      --text-light: #f3f4f6;
      --text-muted: #6b7280;
      --border-color: #e5e7eb;
      --card-bg: #ffffff;
      --font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    }
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body { font-family: var(--font-main); background-color: var(--bg-light); color: var(--text-dark); line-height: 1.6; }
    a { color: inherit; text-decoration: none; transition: color 0.3s; }
    a:hover { color: var(--primary); }
    .container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

    
    .site-header { background: #fff; border-bottom: 1px solid var(--border-color); position: sticky; top: 0; z-index: 100; box-shadow: 0 2px 4px rgba(0,0,0,0.02); }
    .header-container { display: flex; align-items: center; justify-content: space-between; height: 70px; }
    .logo { display: inline-flex; align-items: center; gap: 12px; text-decoration: none; }
    .logo img { display: block; height: 40px; width: auto; max-width: 160px; object-fit: contain; flex-shrink: 0; }
    .logo span { display: inline-block; font-size: 18px; font-weight: 800; line-height: 1; color: var(--text-dark); white-space: nowrap; }
    .logo span::after { content: ' 吃瓜网'; color: var(--primary); font-size: 14px; font-weight: 500; }
    .desktop-nav { display: flex; gap: 24px; font-weight: 600; font-size: 15px; }
    .desktop-nav a { padding: 8px 4px; border-bottom: 2px solid transparent; }
    .desktop-nav a:hover { border-bottom-color: var(--primary); }
    .menu-toggle-btn { display: none; background: none; border: none; cursor: pointer; color: var(--text-dark); }

    
    .drawer-overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.5); z-index: 999; display: none; opacity: 0; transition: opacity 0.3s; }
    .drawer-overlay.active { display: block; opacity: 1; }
    .mobile-drawer { position: fixed; top: 0; left: -280px; width: 280px; height: 100%; background: #fff; z-index: 1000; transition: left 0.3s ease; box-shadow: 4px 0 10px rgba(0,0,0,0.1); display: flex; flex-direction: column; }
    .mobile-drawer.active { left: 0; }
    .drawer-header { display: flex; justify-content: space-between; align-items: center; padding: 20px; border-bottom: 1px solid var(--border-color); }
    .drawer-close-btn { background: none; border: none; cursor: pointer; font-size: 24px; color: var(--text-muted); }
    .drawer-body { padding: 20px; overflow-y: auto; flex-grow: 1; }
    .mobile-nav { display: flex; flex-direction: column; gap: 16px; font-size: 16px; font-weight: 600; }
    .mobile-nav a { padding: 8px 0; border-bottom: 1px solid var(--bg-light); }

    
    .sub-nav-bar { background-color: var(--bg-dark); color: #fff; padding: 8px 0; font-size: 14px; }
    .sub-nav-content { display: flex; justify-content: space-between; align-items: center; }
    .sub-nav-keywords span { color: var(--primary); font-weight: bold; margin-right: 8px; }
    .sub-nav-keywords a { color: var(--text-light); margin-right: 12px; font-size: 13px; }

    
    .about-header { text-align: center; padding: 60px 0; background: #fff; border-bottom: 1px solid var(--border-color); margin-bottom: 40px; }
    .about-header h1 { font-size: 32px; font-weight: 800; color: var(--text-dark); margin-bottom: 15px; }
    .about-header p { font-size: 16px; color: var(--text-muted); max-width: 600px; margin: 0 auto; }

    .about-grid { display: grid; grid-template-columns: 2fr 1fr; gap: 40px; margin-bottom: 60px; }
    .about-content { background: #fff; padding: 30px; border-radius: 8px; border: 1px solid var(--border-color); }
    .about-content h2 { font-size: 22px; font-weight: 800; margin-bottom: 15px; color: var(--text-dark); border-bottom: 2px solid var(--primary); display: inline-block; padding-bottom: 4px; }
    .about-content p { font-size: 15px; color: var(--text-dark); margin-bottom: 20px; line-height: 1.8; }
    .about-content ul { margin-left: 20px; margin-bottom: 20px; display: flex; flex-direction: column; gap: 8px; }
    
    .timeline { position: relative; padding-left: 20px; border-left: 2px solid var(--border-color); display: flex; flex-direction: column; gap: 20px; margin-top: 30px; }
    .timeline-item { position: relative; }
    .timeline-item::before { content: ''; position: absolute; left: -26px; top: 6px; width: 10px; height: 10px; border-radius: 50%; background: var(--primary); border: 2px solid #fff; }
    .timeline-year { font-weight: 800; color: var(--primary); font-size: 16px; margin-bottom: 4px; }
    .timeline-desc { font-size: 14px; color: var(--text-muted); }

    
    .about-sidebar { display: flex; flex-direction: column; gap: 30px; }
    .card-contact { background: var(--primary); color: #fff; padding: 25px; border-radius: 8px; }
    .card-contact h3 { font-size: 18px; font-weight: 800; margin-bottom: 15px; }
    .card-contact p { font-size: 14px; margin-bottom: 10px; opacity: 0.9; }

    
    .site-footer { background-color: var(--bg-dark); color: var(--text-light); padding: 50px 0 20px; border-top: 5px solid var(--primary); font-size: 14px; }
    .footer-container { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
    .footer-brand { display: flex; flex-direction: column; gap: 15px; }
    .footer-brand .logo span { color: #fff; }
    .footer-brand .logo span::after { content: ' 吃瓜社区'; color: var(--primary); }
    .footer-desc { color: var(--text-muted); font-size: 13px; line-height: 1.6; }
    .footer-links h4, .footer-info h4 { font-size: 16px; font-weight: bold; margin-bottom: 18px; color: #fff; position: relative; padding-bottom: 8px; }
    .footer-links h4::after, .footer-info h4::after { content: ''; position: absolute; bottom: 0; left: 0; width: 30px; height: 2px; background: var(--primary); }
    .footer-links ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }
    .footer-links a { color: var(--text-muted); }
    .footer-links a:hover { color: #fff; }
    .footer-info p { color: var(--text-muted); margin-bottom: 10px; }
    .footer-info a { color: var(--primary); text-decoration: underline; }

    .footer-bottom { border-top: 1px solid rgba(255,255,255,0.05); padding-top: 20px; display: flex; flex-direction: column; gap: 20px; }
    .friend-links { background: rgba(255,255,255,0.02); padding: 15px; border-radius: 6px; }
    .friend-title { font-size: 13px; font-weight: bold; color: #fff; margin-bottom: 10px; }
    .friend-content { display: flex; flex-wrap: wrap; gap: 12px; }
    .friend-content a { font-size: 12px; color: var(--text-muted); }
    .friend-content a:hover { color: var(--primary); }
    .copyright { text-align: center; font-size: 12px; color: var(--text-muted); }

    @media (max-width: 768px) {
      .desktop-nav { display: none; }
      .menu-toggle-btn { display: block; }
      .about-grid { grid-template-columns: 1fr; }
    }