Collapse plugin navbar items on small viewports

[Alanaktion]

When plugins add root navbar items, the width required increases, which breaks tablet-sized layouts quickly. Even a single nav item can break some layouts, and multiple items breaks on even large widths. I'd like to collapse the items that don't fit into a menu, likely with just an ellipsis as the label. I've been looking into ways to do this, and I'm pretty sure it will require some messy JavaScript, but if there is a CSS solution, I'd love to use that instead.