UV version:

 universalviewer@v4.0.17

I'm submitting a:

• bug report => please fork one of these codesandbox examples with a repro of your issue and include a link to it below
• feature request => please use the user stories repo
• support request => Please do not submit support requests here, use stackoverflow

Current behavior:
When the UV is displayed on a small screen (e.g. a mobile device or simply a very small browser window), the responsive behavior is hiding side panels without offering any way to access them. This is particularly problematic for things like the AV component when a multi-part item is involved (e.g. manifest https://api.bl.uk/metadata/iiif/ark:/81055/vdc_100133103553.0x000002/manifest.json ), because the left side panel with navigation between parts goes away, and there is no way to view anything except the first part.

A related issue is that the right side panel containing metadata also goes away. In the OpenSeadragon component, an info button appears at the bottom of the page which can be used to access metadata, but this info button is absent from other extensions (at very least, this was confirmed to be a problem in the AV component, but I suspect it may carry across to others as well).

Expected behavior:

All functionality should be accessible in mobile as well as via desktop mode.

Steps to reproduce:

Open manifest https://api.bl.uk/metadata/iiif/ark:/81055/vdc_100133103553.0x000002/manifest.json and shrink your browser window. You cannot change parts or view metadata.