/* 底部导航样式 */
        .footer-nav {
            background-color: white;
            padding: 60px 0 30px;
            margin-top: 80px;
        }
        
        .footer-nav h3 {
            font-size: 1.2rem;
            font-weight: bold;
            margin-bottom: 20px;
            color: var(--dark-color);
        }
        
        .footer-nav ul {
            list-style: none;
            padding: 0;
            margin: 0;
        }
        
        .footer-nav li {
            margin-bottom: 10px;
        }
        
        .footer-nav a {
            color: #666;
            text-decoration: none;
            transition: color 0.3s;
        }
        
        .footer-nav a:hover {
            color: var(--primary-color);
        }
        
        .footer-nav .external-link::after {
            content: " ↗";
            font-size: 0.8rem;
            color: #999;
        }
        
        .footer-copyright {
            background-color: white;
            padding: 30px 0;
            border-top: 1px solid #eee;
            margin-top: 40px;
        }
        
        .footer-logo {
            font-size: 1.5rem;
            font-weight: bold;
            color: var(--primary-color);
        }
        
        .footer-copyright p {
            margin: 0;
            color: #666;
        }