Why does navigation keep breaking

So I am forced to finally update my site from the old Comicpress. I’m attempting to add Comic Easel to a theme, with a child theme installed, and no matter what I try to do, the navigation widget is broken. It doesn’t automatically center like it seems it should, it has unnecessary borders around everything, and the comic title is in regular text instead of header text for some reason.

I already did this for another website I built and ended up having to hack together a PHP and CSS solution to fix it but I am just pretty sure that’s not the intended way of doing it, plus it’ll be very prone to breaking.

I cannot find anything about this anywhere in any documentation.

Am I doing something wrong here? Why is the nav widget broken?

http://test.housepetscomic.com/

https://ww.wp.xz.cn/plugins/comic-easel/