Tabs Element - First Tab's border is cut off on the left side.

Greetings! I have created a tab element and included a border with the tabs through CSS. I've tried changing margin CSS and a few other things but can't seem to fix the cut off border in the element. You can see the issue in the screenshots.

*Note second screenshot shows second tab with complete border. The first one is the only one with the problem.

Hope you all can help!

Much Love,
Ciro