CSS font style

[zoetv]

Hello,
I wish to change the font in the chat and chat title to a custom font -

.franklin, body, button, callout, divider, form, html, input, p, select, textarea, ul {
font-family: "franklin-gothic-urw",sans-serif;
}

or I could use a Google font replacement if necessary.
I've tried to modify the theme.css for cold dark and tried to add custom_css in the shortcode, and am not able to get any results. Please recommend the best way to implement the custom font.

Thank you
Zoë