There was an article a while back on HN about why web designers choose light grey on white background. Basically, it looks fine on their own monitor which has the contrast turned way up
For me it’s Dark Reader (https://github.com/darkreader/darkreader) which can be installed on at least chrome and Firefox desktop browsers, and safari and Kagi on iPhones.
I use it to keep from getting flashbanged by my monitor. In this case it also fixes the above site, however some websites need the color filter mode changed to work better, so realistically I’m not ending up with less fixing of websites, just easier fixing.
The css is ".prose-invert" and there's a ".prose" that looks better, I wonder if something threw a switch to make it "invert" when it should be ".prose" because you're right, this is unreadable as-is. Interesting read though.
Its black background and white text on my screen. So either the OP saw the comments and fixed it or some people in this thread have weird settings. Or maybe I have weird settings...hmmm.