This is great. My only feedback is that, yes you're using text only but please don't shy away from minor CSS changes that can make the site look more pleasant. I have been working my homepage (https://usmanity.com) for years to make it minimal, organized, and still pleasant to look at.
I agree minor CSS changes make sense, and you'll see I've applied some styling for dark mode, use of serif font, maximum page width and minor other things on specific pages.
But I've chosen not to mess with things line text size and line height. More power to the user (agent)! Also, pleasant is in the eye of the beholder and I like it this way.
