You could change the default fonts throughout the publication, but as you
want to change only the navbar font, just select the text on each button,
and change the font. Do all the buttons on the first page, and the other
pages will change automagically.

DavidF

what version of publisher are you using? Are you using a template or blank
page?
I find that the nav bar text is determined by the template I use and the
default fonts I use for that publication. To set a default font for a
publication it depends on your version of publisher. I'm not sure you can
set a default for all publications so I've created a template for myself
with all the default settings I like to use.
Sorry I couldn't be more help.

Carol