Is your suggestion for improvement related to a problem? Please describe.
I'm always frustrated when I move the jabref UI from one large screen to a small screen (screen/monitor) because the width for the sidebar for groups does not adapt to screensize.

Describe the solution you'd like
it would suggest JabRef calculates the proportion of the side bar relative to the window size (when the width is manually changed, store it proportionally). when the window is moved and changed by the OS, then the proportion of the width should also adapt.

see here the "same" window on two screens.

p.s. sorry - i did not know what to search for - across the already existing issue, to be able to link it meaningfully.