Too much vertical spacing between username and first message
There's a lot of spacing between the username and the first message, which looks weird. The messages themselves are also a bit too far apart.
I'd reduce the margin on the header from 10px to 3px (see below), and drop the spacing between the messages (couldn't find how to do that in Inspector).
Fractal Nightly 6-7a35b0ac, Fedora 39