I don't know much about CSS, but I think what happened is that their source for the fonts have taken the files down. For instance, one of the referenced fonts i

I don't know much about CSS, but I think what happened is that their source for the fonts have taken the files down. For instance, one of the referenced fonts is http://dshap.com/fonts/Gotham-Book.otf http://dshap.com/fonts/Gotham-Book.otf which now yields a 404.