.gallery-pictures {
  list-style: none;
  max-width: 30rem;
  padding: 0;
}

.gallery-pictures > li {
  border: 1px solid transparent;
  height: auto;
  margin: 0 -1px -1px 0;
  overflow: hidden;
  width: calc(100% / 3);
}

.gallery-pictures > li > img {
  cursor: zoom-in;
  width: 100%;
}