It’s really hard to tell which document tab is active.
Which tab is currently active is nearly imperceptible. You can only notice this with a faint highlight and the white X. The active tab should have a contrasting border (white if black, and black if white) so that it pops.
Further, some tabs have colored fonts to identify their file type, these stand more than the active tab, and exacerbate the issue.
Please provide an option for the user to implement this style behavior if you won’t implement this significant UX improvement.
To give you an idea, when Cursor is editing files, it often takes me 5-15s just to realize what file it is editing. The emphasis is too little to be useful. My eyes do a lot of wandering and there is little confirmation.
This is one of the biggest issues with tabs, in general.
Sincerely, a designer.