Board Thread:Support Requests - Designing Your Wiki/@comment-24204753-20161115181810/@comment-25295528-20161115191123

Sorry, I missed that bit. If you mean the entire border around the tabber, it would be this

.tabbertab { border: pixel, state, color !important; }

If you mean lines in general, "border" properties usually refer to that. Remember, when using "border:", give a pixel (thickness of the line) value, a state (solid line, dashed line, dotted line, etc) and a color.

Don't forget, there are hundreds of properties that can be played around with, I'm just outlining the basics. You can check out this page which lists a huge variety of CSS properties. Just be wary only some work for certain selectors :)