Adding Helvetica Neue Font via CSS Editor

2-3 years ago when I was a frequent Prezi user, I was able to add Helvetica Neue (which is the standard font our company uses for all documents & presentations), via the CSS Editor. Its was great, and easy.

Tried to do this today, and it seems to be no longer possible? Can this be?
The range of fonts available now, are pretty random… whatever happened to Georgia and Tahoma etc? These are pretty standard fonts.