Much like you would see with many document programs like OpenOffice. It doesn't have to be a very complex listing; just a way to change font size, color, boldness, and add things like italics and underlining. Not only would it help those of us with bad eyesight (I have both diabetes and am nearsighted and the size and often color of the text has me hunching close and squinting more than I should), but it would let people add their own 'theme' to what they're reading as they play along. Also, in dark mode, some of the text doesn't really contrast quite enough with the dark background, making it even harder to see... at least for me.