/* 图片容器：相对定位，方便按钮居中 */
    .video-card {
      position: relative;
      display: inline-block;
      cursor: pointer;
      overflow: hidden;
      border-radius: 8px; /* 圆角可选 */
    }

    /* 图片本身 */
    .video-card img {
      display: block;
      width: 100%;
      height: auto;
      transition: all 0.3s ease;
    }

    /* 悬停遮罩：变暗效果 */
    .video-card::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: rgba(0, 0, 0, 0); /* 默认透明 */
      transition: background 0.3s ease;
      z-index: 1;
    }

    /* 播放按钮：默认隐藏 */
    .video-card::after {
      content: '\25B6'; /* 播放图标 ▶ */
      position: absolute;
      top: 50%;
      left: 50%;
      transform: translate(-50%, -50%) scale(0.8);
      color: white;
      font-size: 40px;
      opacity: 0;
      transition: all 0.3s ease;
      z-index: 2;
    }

    /* 悬停时：变暗 + 显示按钮 */
    .video-card:hover::before {
      background: rgba(0, 0, 0, 0.5); /* 变暗程度 0~1 可调 */
    }
    .video-card:hover::after {
      opacity: 1;
      transform: translate(-50%, -50%) scale(1);
    }