Meanwhile this website has learned how to break mouse scrolling.
Which of course completely ignores that a page of paper can't scroll, but I guess doing it in a way where the content is split over multiple "pages" underneath each other is too complicated for a basic website - and would be even more jarring to the average reader.
...appears it's been fixed since my original comment. There's still no scrollbar in the expected place on the side of my browser window though.