It depends what kind of the menu do you use. If the one on demo site, look at the following CSS styles:
/ja_quartz/ja_menus/js_cssmenu/ja.cssmenu.css
#ja-cssmenu li a {
display: block;
text-decoration: none;
font-size: 110%;
color: #586c0a;
padding: 30px 15px;
font-weight: 700;
text-transform: uppercase;
}
Font style is defined in template.css
body {
font-family: “Segoe UI”, “Trebuchet MS”, “Arial”, “Helvetica”, sans-serif;
}
It could be overwritten in #ja-cssmenu li a { } (add !important if font style does not change)
