Responsive & Clean Code - 4 Card Feature Section

Back in March, my attempt at this took about 6 hours. Nearly had a meltdown learning how to make the whole thing responsive.

Doing it today took me about an hour and I'm glad to know that I was able to find a fairly simple solution using my learned skills instead of browsing the internet for it.

Its nice clean code for both html and css in my opinion. But please tell me if you have any tips to shorten some of the code in css.