Frontend Mentor 7th Challenge - Testimonial Grid Section

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

It took quite some time but I was able to complete the challenge and I plan to do better in the next.

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

I couldn't get the CSS background-image property to work for some reason, and I don't understand. I took the problem to my codepen to figure out the issue and found out I messed up the CSS selector, which should have been obvious, but I didn't see it; hence, the challenge took longer than expected. I first tried using the before pseudo-element, which worked but wasn't giving me the desired result.

I know the challenges are supposed to be mobile first but I like to approach it from the biggest screen first and that gave me an unexpected issue. I expected the vh of the desktop to work the same for mobile but it didn't or maybe I just don't understand the concept and implementations well enough. This resulted in me having to figure out how to add a margin to the top and bottom of the grid content and it took about 4hrs to finally get it to work. I believe this is a beginner mistake that would have been quickly fixed by a pro.

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

I'd be happy if someone could explain some of the common challenges with desktop first design when building for both mobile and desktop and how to tackle the problems.