kibana-123/src/ui/public/styles/spinner.less

Kibana is an open source (Apache Licensed), browser based analytics and search dashboard for Elasticsearch. Kibana is a snap to setup and start using. Kibana strives to be easy to get started with, while also being flexible and powerful, just like Elastic

.spinner.ng-hide {
  visibility: hidden;
  display: block !important;
  opacity: 0;
  transition-delay: 0.25s;
}