.gallery-item:nth-child(6n-5) {
  width: calc(50% - 20px);
  margin: 10px;
  background-color: #d2e0e5;
}

.gallery-item:nth-child(6n-4) {
  width: calc(50% - 20px);
  margin: 10px;
  background-color: #e9dce6;
}

.gallery-item:nth-child(6n-3) {
  width: calc(33% - 20px);
  margin: 10px;
  background-color: #efd6bd;
}

.gallery-item:nth-child(6n-2) {
  width: calc(33% - 20px);
  margin: 10px;
  background-color: #d6d5d0;
}

.gallery-item:nth-child(6n-1) {
  width: calc(33% - 20px);
  margin: 10px;
  background-color: #edcfd2;
}

.gallery-item:nth-child(6n) {
  width: 100%;
  margin: 10px;
  background-color: #efebea;
}