I don't know what changed, but tonight, the default side coding changed to 'light', meaning the word are virtually illegible. I was forced to copy each chapter, copy it to MS Word, reformatting the text so it displayed correctly, so I could read another chapter.
I thought that maybe I'd reset something accidentally, but switching to my laptop, it appears to be happening irrespective of device or browser. I guess I'll have to dive into my personal story settings once again, which I haven't done for ages. After all, once you have them set up the way you like, who do I need to continually go back and check them for?