ember-sortable/addon/styles/components/sortable-group.css

Sortable UI primitives for Ember.

.visually-hidden {
  position: absolute !important;
  height: 1px;
  width: 1px;
  overflow: hidden;
  clip: rect(1px 1px 1px 1px); /* IE6, IE7 */
  clip: rect(1px, 1px, 1px, 1px);
  white-space: nowrap; /* added line */
}