/* ================== 【8张行业背景图片修改接口】 ==================
     请在此处将 url('...') 内的网址替换为您的真实应用场景图（推荐 400px * 260px） */
  .app-img-1 { background-image: url('//ueeshop.ly200-cdn.com/u_file/UPBE/UPBE114/2606/03/photo/0d770d0f89.png'); }
  .app-img-2 { background-image: url('//ueeshop.ly200-cdn.com/u_file/UPBE/UPBE114/2606/03/photo/HVAC.png'); }
  .app-img-3 { background-image: url('//ueeshop.ly200-cdn.com/u_file/UPBE/UPBE114/2606/03/photo/6b0964beb8.png'); }
  .app-img-4 { background-image: url('//ueeshop.ly200-cdn.com/u_file/UPBE/UPBE114/2606/03/photo/7950159f40.png'); }
  .app-img-5 { background-image: url('//ueeshop.ly200-cdn.com/u_file/UPBE/UPBE114/2606/03/photo/d9c74b52c6.png'); }
  .app-img-6 { background-image: url('//ueeshop.ly200-cdn.com/u_file/UPBE/UPBE114/2606/03/photo/1f12bb4b71.png'); }
  .app-img-7 { background-image: url('//ueeshop.ly200-cdn.com/u_file/UPBE/UPBE114/2606/03/photo/80fa2a1adc.png'); }
  .app-img-8 { background-image: url('https://images.unsplash.com/photo-1557223562-6c77ef16210f?auto=format&fit=crop&w=500&q=80'); }

  /* 基础容器 */
  .delta-app-section {
    padding: 80px 20px;
    background-color: transparent; /* 完美融合浅色系网页 */
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  }
  .delta-app-container {
    max-width: 1200px;
    margin: 0 auto;
  }
  
  /* 头部标题 */
  .delta-app-header {
    text-align: center;
    margin-bottom: 55px;
  }
  .app-sub-tag {
    font-size: 12px;
    color: #005da6; /* Delta 蓝 */
    font-weight: 700;
    letter-spacing: 2px;
    display: block;
    margin-bottom: 10px;
  }
  .delta-app-header h2 {
    font-size: 36px;
    color: #111111;
    font-weight: 700;
    margin: 0 0 15px 0;
    letter-spacing: -0.5px;
  }
  .app-title-line {
    width: 45px;
    height: 3px;
    background-color: #005da6;
    margin: 0 auto;
  }
  
  /* 智能标准 4 列八宫格网格 */
  .delta-app-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
  }
  
  /* 单个应用场景卡片实体 */
  .delta-app-card {
    background: #ffffff;
    border-radius: 12px;
    border: 1px solid #e2e8f0;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.01);
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    display: flex;
    flex-direction: column;
  }
  
  /* 上层：纯图片橱窗（图文彻底分离核心） */
  .app-card-img {
    width: 100%;
    height: 180px;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    transition: transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
  }
  
  /* 下层：纯白文字区 */
  .app-card-info {
    padding: 24px;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    background: #ffffff;
  }
  
  /* 行业标题 */
  .app-card-info h3 {
    font-size: 18px;
    color: #0f172a;
    font-weight: 600;
    margin: 0 0 16px 0;
    letter-spacing: -0.2px;
    transition: color 0.3s ease;
  }
  
  /* 细分行业子列表 */
  .app-sub-list {
    list-style: none;
    padding: 0;
    margin: 0;
  }
  .app-sub-list li {
    font-size: 14px;
    color: #64748b;
    margin-bottom: 8px;
    position: relative;
    padding-left: 14px;
    line-height: 1.4;
  }
  .app-sub-list li:last-child {
    margin-bottom: 0;
  }
  
  /* 细分场景前的精致引导圆点 */
  .app-sub-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 7px;
    width: 5px;
    height: 5px;
    background-color: #cbd5e1; /* 默认中庸灰 */
    border-radius: 50%;
    transition: background-color 0.3s ease, transform 0.3s ease;
  }
  
  /* ================== 丝滑的高级 Hover 动效 ================== */
  
  .delta-app-card:hover {
    transform: translateY(-6px);
    border-color: rgba(0, 93, 166, 0.15);
    box-shadow: 0 15px 30px rgba(0, 93, 166, 0.05);
  }
  
  /* 图片向内微调放大，极具镜头感 */
  .delta-app-card:hover .app-card-img {
    transform: scale(1.04);
  }
  
  /* 行业主标题顺滑切换为 Delta 专属点缀红 */
  .delta-app-card:hover .app-card-info h3 {
    color: #C1272E;
  }
  
  /* 列表前的小圆点瞬间激活为 Delta 科技蓝并轻微放大 */
  .delta-app-card:hover .app-sub-list li::before {
    background-color: #005da6;
    transform: scale(1.2);
  }
  
  /* ================== 笔记本电脑与中屏适配 (1024px 以下) ================== */
  @media (max-width: 1024px) {
    .delta-app-section { padding: 60px 25px; }
    /* 4列降级变为2列，防止格子过窄导致文字折行过于严重 */
    .delta-app-grid {
      grid-template-columns: repeat(2, 1fr);
      gap: 20px;
    }
    .delta-app-header h2 { font-size: 32px; }
  }
  
  /* ================== 移动端手机完美适配 (768px 以下) ================== */
  @media (max-width: 768px) {
    .delta-app-section { padding: 40px 15px; }
    .delta-app-header { margin-bottom: 35px; }
    .delta-app-header h2 { font-size: 26px; }
    
    /* 强制重组为 100% 宽度的单列流式卡片，最符合手机端单手滚屏的交互 */
    .delta-app-grid {
      grid-template-columns: 1fr;
      gap: 16px;
    }
    
    .app-card-img {
      height: 200px; /* 手机端适当拉高图片比例，呈现视觉大图感 */
    }
    .app-card-info {
      padding: 20px;
    }
    .app-card-info h3 {
      font-size: 17px;
      margin-bottom: 12px;
    }
  }