User blog comment:Kirkburn/Technical Update: April 27, 2015/@comment-4403232-20150428104421/@comment-452-20150429022334

.infobox .tabberlive ul.tabbernav li:first-child { border-left: none; } .infobox .tabberlive ul.tabbernav li { border-left: 1px solid red; }

You'll probably also want to set your font size to font-size: 89%;, which is why the tabs are wrapping.