Sass and Flexbox

I'd love feedback. I know the dimensions are a bit off, but I figured I wouldn't focus so much on perfection this round and move on to something else. I also didn't try the mobile version

I had a ton of issues working with Flexbox for the first time so if anyone wants to sift through the code and critique, it would be very much welcomed! I have a lot more to learn, that's for sure!

There are two stylsheets. Main.css is minified, and style.css was run through unminify.com so it may not be the most readable. Thanks!