HTML Semantics, CSS

I initially used the class 'container' but I was not able to get a different background color for the qr code box and so used the class 'card'. I also found using box was not allowing the background color show on the block. I feel I could have still used either of these two though...pls tell me how?

This is my attempt without looking at any other solutions to this challenge because I wanted to achieve this solution all by myself. I know it is not an exact replica of the design and welcome best practises solutions to be shared with me.