kibana-123/src/ui/public/angular-bootstrap/modal/backdrop.html

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

<div class="modal-backdrop fade {{ backdropClass }}"
     ng-class="{in: animate}"
     ng-style="{'z-index': 1040 + (index && 1 || 0) + index*10}"
></div>