QR code component built using Flexbox

What are you most proud of, and what would you do differently next time?

This is a first project in which I had the opportunity to learn basics of Sass. In the future it could be rebuilt using either Bootstrap or Tailwind CSS.

What challenges did you encounter, and how did you overcome them?

I had some issues trying to put the attribution footer at the bottom of the page while still centering the qr code with some vertical margins when displayed on a screen with limited vertical space. Solution was to apply flex-shrink for the footer and putting the qr code card in an outside flexbox container with flex:1 and then applying padding to this container.

What specific areas of your project would you like help with?

I am still bit unsure about best practices regarding font sizes and px values in general, I wonder in which cases it is best to substitute them with em/rem.