Bold code font is wider than non-bold (on Firefox)

[mgeier]

First of all, thanks for this great theme, it is looking really good!

I've used it as an example theme for my Sphinx extension nbsphinx, see https://nbsphinx.readthedocs.io/en/typlog-theme/

There is a problem with the "code" font, though (at least on Firefox).

Bold characters are wider than non-bold ones, as can be seen here: https://nbsphinx.readthedocs.io/en/typlog-theme/code-cells.html#ANSI-Colors

Here's how it looks on Firefox:

I also tried it on Chrome, where the columns are correctly aligned.