ShiftNav inherits the font from your theme, so the simplest way to set ShiftNav’s font is just to set a font on the body
body{ font-family: Helvetica, sans-serif;} |
You can also target ShiftNav specifically
.shiftnav{ font-family: Helvetica, sans-serif;} |
However, sometimes a theme or another plugin will add styles that affect the menu (for example, for .menu-item), so you may need to add more specific selectors to override the font in those cases.