.slide-1 {
  background-image: url("../img/catalog-images/slide-4.jpg");
}

.slide-2 {
  background-image: url("../img/catalog-images/slide-1.jpg");
}

.slide-3 {
  background-image: url("../img/catalog-images/slide-2.jpg");
}

.slide-4 {
  background-image: url("../img/catalog-images/slide-3.jpg");
}