.gridbit {
  background-color: rgba(0, 0, 0, 0.8);
  border: 1px solid rgba(255, 255, 255, 0.8);
  width: 200px;
  height: 150px;
  position: relative;
  display: inline-block;
  overflow: hidden;
  margin: 0;
}

.gridbit img {
  display: block;
  position: absolute;
  top: 50%;
  left: 50%;
  height: auto;
  width: 100%;
  transform: translate(-50%, -50%);
}

@media only screen and (max-width: 750px) {
.gridbit{
  width: 100%;
}

.thumb {
    width:100%;
    height:100%;
    object-fit: cover;
}