Where is the font actually sourced into main.css?

[fridde]

Sorry for asking a rather simple question I have been struggling with for some time:
I was expecting either base.html or main.css to include some @import of data-woff2.css (or the other precompiled font files), but I have no idea how the browser is supposed to know where to look for these files.

Is there some implicit import going on that I have missed?

I mean, my browser seems to use the typeface just fine since it's already installed in my OS, but I still wonder.