How do I use the administrative theme? I'm building a custom Drupal theme and wondering if there is a way to get the modal windows to use the default admin theme. I'm using the Layout builder module with a custom block that uses the Media Library module and it uses jQuery UI classes.

This is also for the modal content like the media modal.
I think Media Library Theme Reset may be what you're looking for. From the module description:


  this module takes on the responsibility of replicating Seven's CSS and
  attaching it, as a library, in the context of the Media Library, when
  accessed via Layout Builder.