Asides at bottom of page get cut off

[ascholerChemeketa]

Email report from Jeremy Sylvestre:
Go to
https://sites.ualberta.ca/~jsylvest/books/DLA1/section-inverses-theory.html

Scroll all the way to the bottom: there's an aside at the very bottom of the page.

At least for me (Chromium on Linux):

If my browser window is wide enough that the aside is fully in the right margin of the page, then the aside content is cut off. Hovering the mouse over the aside or clicking to focus it does not help.

If my browser window is narrow enough that the aside is not fully in the right margin, then hovering the mouse over the aside lengthens the page and allows the aside content to be fully displayed. Clicking the aside causes it to move into the page and fully open, again allowing the content to be fully displayed, but the Prev/Top/Next buttons are obscured.