.thumbnails {
  display: flex;

  position: absolute;
  left: 50%;
  bottom: 20px;
  
  transform: translateX(-50%);
}

.thumbnails li {
  display: inline-block;

  list-style: none;

  margin: 0 20px;
}

.thumbnails img:hover,
.thumbnails img:focus {
  transform: translateY(-15px);
}

.thumbnails li img {
  max-width: 40px;

  transition: 0.5s;

  cursor: pointer;
}

@media(max-width: 991px) {
  .thumbnails li img {
    max-width: 30px;
  }
}

@media(max-height: 740px) {
  .thumbnails li img {
    max-width: 30px;
  }
}