Responsive four card feature page using flexbox

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

I'm happy I was able to get something that works pretty well and is pretty fluid. The layout flows pretty nice from desktop resolution down a small-ish mobile display size.

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

The only real challenge I ran into here was working with flexbox and getting the 3 column layout working for the desktop display. I was able to get it working well by way of using a couple wrappers, but I'd really like to find a way to do this without needing to mess with the html.

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

Any feedback is welcome. Especially with regards to what I mentioned above.