QR code component

Hey, thanks to anyone reviewing my solution.

One of the main things I was wondering about was how to decide on a border radius of an inner element (in this case the image), once a border radius for the outer section (in this case the card) is already decided, or vice-versa.

Another thing I would appreciate feedback with is whether I'm using the correct units for the correct properties. I know font-size should usually be rem, and I think padding should be rem too. But I'm not too sure if there are any hard rules about what units should be used for any other properties.

Thanks again.