/* For validation */
.select2-selection.invalid[aria-disabled="false"]{
  border: 1px solid red !important;
}
/* For remove item button (TAG changed: SPAN to BUTTON [4.0.13 -> 4.1.0-beta.1]) */
.select2-selection__choice__remove{
  background-color: transparent;
  border: none;
  font-size: 1em;
}