.fader {
  position: relative;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background-color: transparent;
}

.fader__item {
  display: block;
  position: absolute;
  top: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  transition-property: opacity;
  transition-duration: 3s;
}
.fader__item.in {
  opacity: 1;
}