Since that page doesn't seem to be loading, here is a gist with the relevant bookmarklet. You click it once to turn on Fount, click a piece of text on the page, and it will show you in the top right the font-family, font-size, etc. (as it actually rendered on your machine vs. what the CSS says it should do):
https://gist.github.com/mvarrieur/444e8e45c31f241e5b37334d94...