The first thing I noticed when I visited the site is that jQuery is not being loaded (check your browser console and you’ll see the 404 not found error).
but the browser is saying that it can’t find the file, so either the location is wrong or the file is missing. The very next line in the console is an error message complaining that the jQuery variable ($) isn’t defined (because the library isn’t loaded) and that’s why your font changing script isn’t working.