How to make bootstrap table thread bb?

Question

Bootstrap

codepen.io/mrusklon/pen/WoRdey
can't figure out how to make border-bottom of thead
or first tr border-top

Answer 1

it turned out that everything works, only the bootstrap has a 2px border, if you set the same one, it does not overlap, set it to 3px and everything went

Answer 2

I don't understand what is the meaning of the question? the link is already fully working version written