* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        /* 整体背景与字体 */
        body {
            background: #f5f7fb; /* 温和外部背景，原卡片容器内部白底保持不变 */
            font-family: 'Arial', 'Helvetica Neue', sans-serif;
            line-height: 1.4;
        }

        /* 为了让卡片阴影和圆角更自然，保留原始风格，同时响应式适配 */
        .engineered-solutions {
            background: #ffffff;
            padding: 60px 20px;
            font-family: Arial, sans-serif;
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
            display: flex;
            flex-wrap: wrap;
            gap: 20px;
            justify-content: center;
        }

        /* 卡片公用样式 */
        .card {
            flex: 1 1 260px;
            max-width: 280px;
            background: #f7f9fc;
            border-radius: 14px;
            overflow: hidden;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
            transition: transform 0.2s ease, box-shadow 0.2s ease;
        }

        /* 让第四张卡片与众不同 —— 保留原有边框高亮但不过分突兀 */
        .card-featured {
            border: 2px solid #dbe3ef;
            box-shadow: 0 6px 18px rgba(0, 0, 0, 0.08);
        }

        /* 悬停微效果提升交互感 */
        .card:hover {
            transform: translateY(-4px);
            box-shadow: 0 12px 24px rgba(0, 0, 0, 0.1);
        }

        .card-img {
            width: 100%;
            height: 180px;
            object-fit: cover;
            display: block;
        }

        .card-content {
            padding: 20px;
        }

        .card-title {
            font-weight: bold;
            color: #222;
            margin-bottom: 6px;
            font-size: 1rem;
        }

        .arrow-symbol {
            color: #1f3b64;
            font-weight: bold;
            margin: 6px 0;
            font-size: 1.1rem;
        }

        .card-desc {
            color: #333;
            line-height: 1.6;
            font-size: 0.95rem;
        }

        /* 响应式优化: 手机下维持居中 */
        @media (max-width: 640px) {
            .engineered-solutions {
                padding: 40px 16px;
            }
            .card {
                max-width: 100%;
                flex: 1 1 100%;
            }
            .container {
                gap: 24px;
            }
        }

        /* 为了让第四张卡片内描述更具可读性，添加一点行距细节 */
        .strong-text {
            font-weight: 500;
        }