Changing Link Size

Found in the theme’s style.css file around line 1520 and it looks like this:

.main-navigation li {
	background-image:none;
	margin-top: 20px;
	margin-top: 1.250rem;
	padding-left:0;
	font-family: ubuntu,sans-serif;
	font-size: 15px;
	font-size: 0.938rem;
	line-height: 1.42857143;
}

The font is using both px and rem (relative size). The rem value is the same as 15px, but you can remove the rem line and use only the px if that is more comfortable for you. This site http://www.pxtoem.com is what you can use to convert px to em and vice versa.

For making changes to core theme files, it’s recommended using a child theme which is available in a Child theme tutorial here http://www.styledthemes.com/encounters-lite-setup