.region--sticky--col {
  position: sticky;
  width: 100%;
  z-index: 1000;
}

@media screen and (min-width: 625px) {
  .region--sticky--col {
    position: absolute;
    width: auto;
    right: 100%;
    top: 0;
  }
  .region--sticky {
    border-right-style: solid;
    border-right-width: 1px;
  }
}

.region--sticky .block {
  width: auto;
}