Is this the same issue as #54 ?

No. That PR changes this theme to use font-family: Arial, sans-serif to work around a Chrome bug.

This one is suggesting we change to something like: font-family: -apple-system, BlinkMacSystemFont, avenir next, avenir, helvetica neue, helvetica, Ubuntu, roboto, noto, segoe ui, arial, sans-serif; instead, which is a strict superset.

The reasoning why we might want to use such a set of fonts, is presented pretty well on the aforementioned https://systemfontstack.com website. :)

Might this also fix python/devguide#581?

That's because the font-stack is monospace, sans-serif and should instead be monospace, monospace because of a Chrome bug. 🤷🏽

If a PR is welcome, we should probably change the monospace font stack too (there's an example in the link provided, so... that should fix it).

That's because the font-stack is monospace, sans-serif and should instead be monospace, monospace because of a Chrome bug. 🤷🏽

Oh! Here's more info on it: https://stackoverflow.com/a/36540436/724176

That's right: two monospace keywords at the end of the font stack. Nobody knows why this works; it just does.

It also links to a 2010 blogpost about it, and it's not going away anytime soon!