Fix line-height and logo overflow issues on tabs bar

I was made aware about some tabs bar CSS issues in !440 (closed) by @mkljczk, particularly in regards to the displaying of Polish language translations. When I saw the tabs bar in Polish, the CSS was not quite all there. Here's what it looked like:

So, I made a couple small changes to the line-height and removed the overflow: hidden line for the logo. And it now looks much better: