Custom code fonts and other options not working

First of all, clicking the UI buttons to change options doesn't seem to do anything at all, I have to manually change the 0s to 1s in the code.

Then, in order to actually change the font, I have to add the classes .react-code-text and .comment-body pre to the custom code font styling. .blob-code-inner doesn't seem to reference anything at all. This may be the case with the other options as well, but I'm not even sure what they're supposed to do, so I can't tell if they're changing anything or not.