Overriding font menu size in Nation theme

Is there a discussion forum for the Nation theme? I just bought a developer package and would like to customize the font size for the menu items but it seems to override my customizations in teh admin area for the font-size, although not the font-family. For example, I use a customization of the following.

.dexp-menu li a{ font-family: "Montserrat"; font-size: 20pt; font-weight: 600; font-style: normal; line-height: 2.2; }

and it will change the font to Montserrat but the font-zie and line-height are not changed (above example uses large values just so I can notice the difference).