My gut suggests it's a font issue, like librewolf is using a system font and firefox is using embedded or downloaded fonts.
backing that up with a search, I see there's lots of people complaining of font rendering issues of various types in the librewolf subreddit: https://www.reddit.com/r/LibreWolf/search/?q=font
I don't know what your fix is, but I hope this helps guide you.
Let me paraphrase the LNP here:
"Private companies have researched Nuclear and decided it's not cost effective."
"Financial institutions have investigated Nuclear and decided they WILL NOT INVEST."
"But our financial backers at the Mineral Council and the private companies dragging the last of the profit out of their end of life coal power stations are insisting that we continue with our current market AS LONG AS POSSIBLE, so we've decided to announce an extremely long term plan, to scare private investment out of renewables short term."
"Don't worry, between NIMBYs in the target areas, laws surrounding nuclear energy, lack of local expertise and the general unsuitability of Nuclear for our widely dispersed yet small population, we won't actually build more than one of these things."
"Jokes on them, we were only pretending to be retarded."