Responsive QR using CSS Flexbox and mediaqueries

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

As all things i code, my first thought always is "This is pretty easy, i should do it just for shape my skills a little better. 40 min for do it" And then, 2 hours to realize.

Html was pretty simple, but i had to start to struggle with the css. I hate looking sizes for the images, and responsive. But with mediaqueries and % sizes, i could finally made the qr responsive.

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

The images. I really dont like them. The way of making not only fit in the container, but also make them responsive is pretty easy and the same time, tedius as nothing else.

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

I need really to keep practicing css. thats all.