QR Code Page using HTML and CSS

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

Learned how to use Git, however I committed too many times before remembering I could open the index page through the file alone. Know now only to commit when I'm ready instead of using it to check little details.

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

Had a bit of trouble centering the div containing the QR Code on the whole page but learned how to vertically and horizontally centre the div on both phone and bigger screens in the most efficient way.

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

Not so sure on sizing and using px vs % when it comes to displaying elements on different screens, so some advice on that would be helpful.