/* 404内容样式 */
        .error-content {
            flex: 1;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            text-align: center;
            padding: 150px 0 80px;
        }
        
        .error-code {
            font-size: 120px;
            font-weight: 700;
            color: #3498db;
            margin-bottom: 20px;
            text-shadow: 3px 3px 0 rgba(0,0,0,0.1);
            line-height: 1;
        }
        
        .error-message {
            font-size: 28px;
            color: #2c3e50;
            margin-bottom: 30px;
        }
        
        .error-description {
            font-size: 18px;
            color: #7f8c8d;
            max-width: 600px;
            margin-bottom: 40px;
        }
        
        .error-actions {
            display: flex;
            gap: 20px;
            flex-wrap: wrap;
            justify-content: center;
        }
        
        .btn {
            display: inline-block;
            background: #3498db;
            color: white;
            padding: 12px 30px;
            border-radius: 50px;
            text-decoration: none;
            font-weight: 500;
            transition: all 0.3s;
            box-shadow: 0 4px 15px rgba(52, 152, 219, 0.4);
        }
        
        .btn:hover {
            background: #2980b9;
            transform: translateY(-3px);
            box-shadow: 0 6px 20px rgba(52, 152, 219, 0.6);
        }
        
        .btn-outline {
            background: transparent;
            border: 2px solid #3498db;
            color: #3498db;
            box-shadow: none;
        }
        
        .btn-outline:hover {
            background: #3498db;
            color: white;
        }
        
 
        /* 响应式设计 */
        @media (max-width: 768px) {
            nav ul {
                display: none;
            }
            
            .error-code {
                font-size: 80px;
            }
            
            .error-message {
                font-size: 24px;
            }
            
            .error-description {
                font-size: 16px;
                padding: 0 20px;
            }
            
            .error-actions {
                flex-direction: column;
                align-items: center;
            }
        }