Is there a way to collapse the sidebar when the focus leaves the region?

[peterychang]

When the site window is sufficiently small, the sidebars will collapse into popouts. At that point, you can tab navigate through the toc elements. However, you can also tab out of the popout and onto the main page without collapsing it

Example:

Is there a way to either prevent the focus from leaving the sidebar, or collapsing the sidebar when the focus leaves the region?

The same issue occurs with the search overlay.

[drammock]

#1737 explains why it's possible (indeed preferable) for focus to leave the sidebar eventually. See especially this comment

[peterychang]

Thanks! I'll see if this is acceptable on our side. I'll post up another discussion in the case that I actually need to change the behavior here