.app-grid {
    display: grid;
    /* 响应式列：电脑端2列，手机端自动变1列 */
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); 
    gap: 25px;
    margin: 20px 0;
  }

  .app-item {
    margin: 0;
    text-align: center;
    background: #ffffff;
    border-radius: 12px;
    overflow: hidden;
    /* 给整体加一个轻微的阴影，让产品图更突出 */
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
  }

  .app-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.1);
  }

  .app-item img {
    width: 100%;
    /* 强制图片容器符合 4:5 比例 */
    aspect-ratio: 4 / 5; 
    /* 确保图片充满容器且不拉伸，裁剪掉多余边缘 */
    object-fit: cover; 
    display: block;
  }

  .app-item figcaption {
    padding: 15px 10px;
    font-size: 18px;
    font-weight: 700; /* 加粗标题，适合B2B风格 */
    color: #222;
    background: #fff;
  }

  /* 针对手机端的适配调整 */
  @media (max-width: 480px) {
    .app-grid {
      grid-template-columns: 1fr; 
      gap: 20px;
    }
    .app-item figcaption {
      font-size: 16px;
    }
  }