On Firefox, code examples are sometimes 1-2 pixels longer than their viewport, so you can get a fairly pointless scrollbar. See, e.g.,
https://helpmanual.io/man3/printf/One suggestion: how about guessing at hyperlinks. For example, there are a few underlined instances of `size_t' in the printf man page. If you ask for the size_t man page, you get the man page for stdint. Suppose I had a device on my desk that could automate this sort of drudgery for me...
(I did something like this for my patched version of Bwana: https://bitbucket.org/tom_seddon/bwana, original: https://www.bruji.com/bwana/ - works well, at least for the OS X man pages. My code only looks for man pages with the exact name, though, since it runs on demand. If you're doing a preprocess to generate all the pages ahead of time then you could perhaps afford to be more thorough.)
