I hate that folks recommend random extensions. Browsers should include style/css editors (with the ability to save and reload styles later) for accessibility. Since we don't have that, uBlock Origin does a lot of heavy lifting, and can add a dark mode to HN and other sites.

I'd share my ruleset, however, I am missing one. Before I switched PCs (motherboard caught fire) I had one that made everything dark mode, didn't dim the text, and buttons/text inputs/other inputs were also properly inverted. I had to make it myself because googling Hacker News dark mode always led to the same broken themes. I forgot to back it up. Adding dark mode doesn't need a bunch of extensions, and while I'm sure the "stylus" extension is probably useful (I haven't used it, sounds like a CSS override extension), UBO does CSS and JS.

Just my thoughts. Don't mind me.