Menu Text Align Issue

Hi!

I’ll first off confess to being a serious WordPress newbie. I’m using the Store theme to build a site at the moment. My issue relates to text alignment issues within the main nav menu. As a default both menus display all pages. I created custom menus, one to show only store related pages and business related pages on the other. I then assigned those menus to their locations within the customizer. For some reason, when I did that – the text for the primary menu items default aligned to the top of the nav bar rather than the middle (which it was before I had assigned a custom menu). I’ve scoured through the CSS to try and figure out what’s causing it to switch, but being a newbie I’m finding it hard. I can add padding here:

.main-navigation {
clear: both;
display: block;
float: left;
width: 100%;

Which gives the impression of centering the text, but also adds height to the nav bar which I don’t want.

Anyone got any suggestions??