Hello fan1430,
Please follow below steps for change font size:
Login as admin and click customize from header then click on Fonts and increase Menu item size.
Hope this will helps you
Hello there,
By default the maximum boldness level of the body font is limited to 600. It was specified in the following Google font definition:
Source+Sans+Pro:400,400italic,600
in the Appearance > Customize > Fonts > Body fonts > Font name/style/sets.
Please change it to:
Source+Sans+Pro:400,400italic,600,900
To make the main navigation font bolder, you should apply the following CSS code through the Simple Custom CSS plugin or child theme’s style.css.
#mainnav ul li a{
font-weight : bold;
}
Regards,
Kharis