.preview-image {
  position: relative;
  width: 100%;
  height: 0;
  padding-bottom: 56.25%; /* 16:9 */
  overflow: hidden;
  border: medium solid #1EAEDB;
}

.preview-image:hover {
  border: medium solid #137391;
}

.preview-image img {
  /* centered position */
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%,-50%);
  /* keep aspect ratio */
  object-fit: cover;
  /* make sure frame is covered */
  min-width: 100%;
  min-height: 100%;
  /* but limit scaling */
  max-width: 125%;
  max-height: 125%;
}