The lines that say
Change 1/3
DIFF
Could be used for more
Maybe when the left sidebar is removed and there aren't two panes that need titles, we stop displaying DIFF and put a sticky header there so the user can know where in the diff they are without the sidebar reminding them.
#8 proposes reducing the file divider to one line; maybe we give that a background and pin it to the top of their viewport until the next file divider pushes it up out of the viewport?
That still leaves it feeling a little empty with the sidebar present and only DIFF in that row, but it would at least be an improvement.
I think can try putting Change N/N in the top row, right of
round-aa209f6447a7e37e54f8245225d164b9.