Best way to change font?

Hi, I’m new to css and not sure what the best way is to change the font that displays inside the progress bar. I’ve gone into css/wppb.css, and changed this line:

div.wppb-wrapper div.inside { margin: 0 auto; line-height: 18px; color: #ffffff; font-weight: italic; position: absolute; z-index: 1; width: 400px; text-align: center; }

To this:

div.wppb-wrapper div.inside { margin: 0 auto; line-height: 18px; color: #ffffff; font-weight: italic; position: absolute; z-index: 1; width: 400px; text-align: center; font-family: Quicksand_Book;}

using a font (Quicksand-Book) which is used elsewhere on my site. But it has no effect.

Does anyone know what I’m doing wrong?