Unable to change font family

Hi,

I would like to use Page Builder with Hathor Pro theme (http://hathorpro.imonthemes.com/). I put a Site Origin Headline widget into a page and under the ‘Font’ field I changed its font family. However, irrespectively of what family I choose, there was no change, the headline was set to the theme font. I wrote the ‘font-family:… ‘ CSS code into the ‘Widget Styles/Attributes/CSS field, but nothing happened. Can anyone help me? Thank you in advance.