[Mainsite] Vertical progress bar goes offscreen (Firefox)

[tarrasqueSorcerer]

I use a fresh version of Firefox (108.0.2). My reader is set up to single page, left to right, header hidden, fit both page dimensions, normal progress bar on the left side.

Sometimes the progress bar goes offscreen downwards - its sections for later pages end up below the screen's edge. With my usual setup (1920×1080, maximized window, not fullscreen) page markers after 39 are cut off (39 displays partially). With smaller page counts, the bar is stretched to fill the screen, as it should.

Changing the size of the browser window (going fullscreen or un-maximizing) changes how much of the bar is visible, but doesn't change its size at all.

Example:
https://mangadex.org/chapter/5788dee1-40a0-4f72-8fac-1930f2e6d011/47

https://imgur.com/a/pw6RuQJ

(smaller window size for convenience)

 

[fourquestionmarksokay]

With my usual setup (1920×1080, maximized window, not fullscreen) page markers after 39 are cut off (39 displays partially).

Can reproduce both with Firefox and Chrome, there's no min-height: 0px (which affects both left and right progress bars) while there's min-width: 0px (this is why the bottom progress bar can squeeze even when the width of the screen is smaller).
I'm not sure if there are other considerations on why there's no min-height: 0px (especially that I didn't test Safari) or it's just an oversight though.

Edit: XenForo apparently doesn't recognize generic CSS font aliases, and apparently ICODE is disabled here.