User-resizable and collapsible panels

Hi,

since our navigation in growing in depth, documents starting in layer 4 become hardly readable on smallish screen resolutions. I usually use 1920x1080, however 1360x768, which I still consider a modern and widely used mobile resolution, is already a problem. My chromebook uses this screen resolution.

Hence, it would be nice to have resizeable and collapsible panels. For my use case, having this for the left panel would be enough, but I can imagine this to be nice for the right panel as well.

I am currently using the flamingo theme on XWiki 10.4.

Best,
Johannes