Space Between Border and Box Shadow?

Hi everyone hope i am posting in the right category. I would like to achieve a tab effect like shown in the picture below. I am quite new to web design and webflow so not quite sure how its done but i assumed that box shadow and border left was used to achieve the effect of scrollbar/selection box on the left picture. Right picture is what i was able to achieve but not quite sure how to add spacing between border and box shadow. It was created using tab menu that was made vertical.

Hi cerkaB and welcome

Check this read only link, hope it helps you.

Hi @shokoaviv thank you for your reply. I am not quite sure if this has helped me, perhaps you posted a wrong link? Thank you

sorry for that, the page in the link was hidden, I revealed it now. try the link again