FAQ accordion using a native CSS and js

I struggled with mail cube keeping on the vertical center and when I used on the .card: { max-weight: 55rem} , there wasn't 55rem of card, when question aswer didn't show. So I've just putten on .card weight: 55rem without max- and the width was kept as need

I unsure of rationaly link on items using `childNodes[<num>] and do i used a mail cube positioning correctly,

Could you share me advice how to make my css more ready for adaptive design