.carousel.banner {
  width: 100%;
  height: 700px; /* 可自定义高度，比如500px、600px */
  overflow: hidden;
  position: relative;
}

.carousel-inner {
  width: 100%;
  height: 100%;
}

.carousel-item {
  width: 100%;
  height: 100%;
  position: absolute;
  left: 0;
  top: 0;
  opacity: 0;
  transition: opacity 0.8s ease; /* 淡入淡出动画时长，0.8秒 */
}

.carousel-item.active {
  opacity: 1;
  z-index: 1; /* 激活的图片显示在最上层 */
}

.carousel-item a {
  display: block;
  width: 100%;
  height: 100%;
  background-repeat: no-repeat !important;
  background-position: center !important;
  background-size: cover !important; /* 统一让所有背景图铺满 */
}
}