What I found difficult: Figuring out how to fit the QR code into the container .div effectively. Turned out to be as simple as setting the width to 100%.
What I'm unsure of: That this approach was the most efficient way of achieving this. When to use px or when the rem.
I edited the footer links to have a hover state of white, but wanted to change the visited color from purple to blue, however when I changed the visited state it removed the hover state. I'm unsure of how to make this happen.