The QA report "When the sidebar is collapsed, the '+ Create' menu gets cut off." The screenshot showed exactly that: with the sidebar collapsed to 60px, the dropdown menu was sliced clean off at the sidebar's right border. Only the first character of "New folder" was visible. The strange part: with the sidebar expanded (244px), the same menu rendered fine. Same code, same 190px menu width. It only broke when collapsed. Where I got stuck My first suspect was z-index — ...