Seems like caching might have to do something with this…
I assume GitHub’s hashFiles may work differently with submodules. But I’m too much of a Git(Hub) novice to be sure.
Removed the GitHub Action cache and triggered the build workflow again. Now the site does seem to be OK lay-out wise. The dark/light mode switching does appear to be broken now.
Looks like the variables weren’t correctly replaced.
This is (part of) the content of the bundled CSS
