That's a shame. The "pref" is whatever the user has set on their device, and I wish more sites would respect that, rather than defaulting to their own "pref".
The whole thing is automatically generated? Does anything persist? If I could be in the middle of reading it, and the next day it's completely different, that's a huge waste of my time.
I've run numerous interactive text adventures through ChatGPT as well, and while it's great at coming up with scenarios and taking the story in surprising directions, it sucks at maintaining a coherent narrative. The stories are fraught with continuity errors. What time of day it is seems to be decided at random, and it frequently forgets things I did or items picked up previously that are important. It also needs to be constantly reminded of rules that I gave it in the initial prompt. Basically, stuff that the article refers to as "maintaining state."
I've become wary of trusting it with any task that takes more than 5-10 prompts to achieve. The more I need to prompt it, the more frequently it hallucinates.
No your writing is fine, and sorry if I'm being a negative nancy. It's just that light text on black backgrounds cause me eye strain so they're not really my cup of tea. The light grey font color does help a litte though. I often experience lines of text being burned into my vision with these themes, and that effect was not as noticeable here.
I am admittedly not a fan of dark themes in general, but I feel they are done right when the dark background is toned down a bit so you're not staring at a pitch black screen. And not just by a few shades.
As an aside, I didn't even know GitHub had a dark theme. I just tried it and it was horrible. Then I switched from dark default to dark dimmed and it was much more tolerable, although I still prefer light.
If readability is truly your pursuit, then it is my humble opinion that you should avoid high contrast white/lightgrey on pitch black colors when designing a dark theme for your app or website, or consider adding a toggle to switch to a light theme. I gave up at the end of the first section of this article because it was just too much.