/* 404内容区域 */
        .error-section {
            flex: 1;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 60px 0;
            text-align: center;
        }
        
        .error-content {
            max-width: 700px;
            margin: 0 auto;
            padding: 40px;
            border-radius: 15px;
            background: white;
            box-shadow: var(--shadow);
            opacity: 0;
            transform: translateY(30px);
            animation: fadeInUp 0.8s ease forwards;
        }
        
        @keyframes fadeInUp {
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }
        
        .error-code {
            font-size: 8rem;
            font-weight: 800;
            color: var(--primary);
            line-height: 1;
            margin-bottom: 20px;
            position: relative;
            display: inline-block;
        }
        
        .error-code::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 100px;
            height: 4px;
            background: linear-gradient(to right, var(--primary), var(--accent));
            border-radius: 2px;
        }
        
        .error-title {
            font-size: 2rem;
            color: var(--dark);
            margin-bottom: 20px;
        }
        
        .error-message {
            font-size: 1.1rem;
            color: #777;
            margin-bottom: 30px;
            line-height: 1.8;
        }
        
        .error-actions {
            display: flex;
            justify-content: center;
            gap: 20px;
            flex-wrap: wrap;
        }
        
        .btn {
            display: inline-block;
            padding: 12px 30px;
            background: var(--primary);
            color: white;
            border-radius: 50px;
            text-decoration: none;
            font-weight: 600;
            transition: var(--transition);
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
            border: none;
            cursor: pointer;
        }
        
        .btn:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
            background: var(--accent);
        }
        
        .btn-outline {
            background: transparent;
            border: 2px solid var(--primary);
            color: var(--primary);
        }
        
        .btn-outline:hover {
            background: var(--primary);
            color: white;
        }
        
      
        /* 响应式设计 */
        @media (max-width: 768px) {
            nav ul {
                display: none;
                position: absolute;
                top: 100%;
                left: 0;
                width: 100%;
                background: white;
                flex-direction: column;
                padding: 20px;
                box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
            }
            
            nav ul.active {
                display: flex;
            }
            
            nav li {
                margin: 10px 0;
            }
            
            .mobile-menu-btn {
                display: block;
            }
            
            .error-code {
                font-size: 6rem;
            }
            
            .error-title {
                font-size: 1.6rem;
            }
            
            .error-actions {
                flex-direction: column;
                align-items: center;
            }
            
            .btn {
                width: 100%;
                max-width: 300px;
                text-align: center;
            }
        }
        
        @media (max-width: 480px) {
            .error-code {
                font-size: 4rem;
            }
            
            .error-title {
                font-size: 1.4rem;
            }
            
            .error-message {
                font-size: 1rem;
            }
        }