I had the setting “save as .rtf” enabled instead of a plain text, so the .css file was faulty. Didn’t know you have to change it on MacOS.
Now it works. Thanks for checking, so I knew the problem was in my end.
And good point on the redundant part of the snippet. I will leave it out.
Ah thanks. Normally I never code, just trying some stuff out to customise my Obsidian experience.
I found the snippet somewhere else. Sadly, I don’t remember the author. I link him if I find the post again.
Thanks for the recommendations, though. I will definitely get one of the programmes just to have a proper one on hand.