i keep telling myself that i'd write a new post once i've finished optimizing but There Are Ways To Optimize The Optimization
(i can't tell if this is rhetorical or a genuine invitation of advice, but) you can use a bit of js to flip on and off a class on the tag representing dark/light, and then just have different css rules depending on what class the html tag has. then for persistence, you can use localStorage
!! genuine invitation of advice, tysm loom! i found a super simple js template that does what you describe, but i'm getting too picky with how i want it to look :') i will persevere
added more site buttons, lmk if i missed yours. currently working on a blog post about degoogling. my eyes hurt