Have had a really nice experience using Dark Reader. Have it on all my browsers (FireFox, Brave, Safari + Mobile). Super useful, and love how it's possible to customise which websites it's on for or off for or in Light or Dark mode for. Controls on Safari are a bit different and doesn't seem to work as successfully (sometimes the text box elements get darkened out completely while background remains seipia, for example), but honestly I suspect the problem lies more with Safari than the extention. While it's free, I've paid for it both on mobile and computer. I think it's worth the money, especially with the stupid levels of time I have to stare at a computer screen.