Removing Border Around Page Tabs/Navigation Bar

If you want to remove the box around your tabs in your horizontal navigation bar, go to Design>Layout>Customize>Advanced. Scroll down to Add CSS.

In the CSS box, copy and add this:

.tabs-cap-top, .tabs-cap-bottom, .tabs-outer, .PageList, .PageList ul, .PageList
.widget-content {border:none !important; background: none !important;
-moz-box-shadow:none
!important;  -webkit-box-shadow:none !important; box-shadow:none
!important;}.tabs-inner .section {border:none !important;}

You can hit the space bar to see if your changes are correct. Then if it is, Save. 

That's it!