.cover-wrapper {
  position: relative;
  width: 100%;
  aspect-ratio: 4/3; /* 可以自己改比例 */
  overflow: hidden;
  background-color: #eee; /* 背景色（底色） */
}

.cover-wrapper.loading::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    100deg,
    #eee 20%,
    #f5f5f5 50%,
    #eee 80%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  z-index: 1;
}

@keyframes shimmer {
  0% {
    background-position: -200% 0;
  }
  100% {
    background-position: 200% 0;
  }
}

.cover-wrapper img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  z-index: 2;
  position: relative;
}

.fade-in-img {
  opacity: 0;
  transition: opacity 0.8s ease-out;
}

.fade-in-img.loaded {
  opacity: 1;
}