semaphore/routes/_components/dialog/VideoDialog.html

<ModalDialog :label :shown background="#000">
  <video poster="{{poster}}"
         src="{{src}}"
         width="{{width}}"
         height="{{height}}"
         aria-label="Video: {{description || ''}}"
         controls
  />
</ModalDialog>
<style>
  :global(#modal-dialog video) {
    object-fit: contain;
    overflow: hidden;
    max-width: calc(100vw - 20px);
    max-height: calc(100vh - 100px);
  }
</style>
<script>
  import ModalDialog from './ModalDialog.html'

  export default {
    components: {
      ModalDialog
    },
    methods: {
      async show() {
        this.set({shown: true})
      }
    }
  }
</script>