.ol-custom-overviewmap,
.ol-custom-overviewmap.ol-uncollapsible {
  top: auto;
  left: auto;
  right: 0;
  bottom: 0;
}

.ol-custom-overviewmap:not(.ol-collapsed) button{
  bottom: auto;
  left: 6px;
  right: auto;
  top: 6px;
}

.ol-custom-overviewmap .ol-overviewmap-map {
  border: none;
  width: 296px;
  height:287px;
}

.ol-custom-overviewmap .ol-overviewmap-box {
  border: 2px solid #ff6666;
  cursor: pointer;
}