Since the author seems to be reading this -- the table of contents isn't displaying correctly for me; it's displaying way off to the left, primarily off the screen; only a tiny part of it is onscreen for me. (The only bits visible read "ngs", "e do", and "e".) This is happening on the site's other pages as well.
This is on Firefox 82.0.3 (64-bit), although possibly worth noting it's the Linux Mint version from their repo rather than the generic version. Linux Mint 20, FWIW.
Oh, good point. Yes, I can change the behavior by resizing the window. Below a certain horizontal width it works fine; above that width it breaks like I described.
Note that my screen is 1920 pixels wide, and the switchover between the two behaviors seems to occur at around 1820 pixels. Narrower than that and it works fine, wider than that and it breaks.
This is so weird. It breaks in Firefox and Edge for >1820px for me too but works fine in Chrome. Looking into this. They appear to display absolutely positioned elements on the page differently for some reason.
This is on Firefox 82.0.3 (64-bit), although possibly worth noting it's the Linux Mint version from their repo rather than the generic version. Linux Mint 20, FWIW.