Can't find css to edit borders

So, I’ve looked at this css for awhile can’t figure out how to change the color of the border between the tabs on the main nav. It has to be in the .nav a or .nav a li, right?

I just can’t find it. It must be border-right and border-left, right?

Please let me know where to edit the code. thx

#navigation .nav li a {
border-right: 1px solid #2c2c2c;
border-left: 1px solid #000000;
}

in file http://worldyardgames.com/wp-content/themes/shelflife/css/layout.css?ver=3.6

on line 192

Thanks! I didn’t even know that that file existed. I was just looking in the style sheet worldyardgames.com/wp-content/themes/shelflife/style.css