Four Card container using flexbox and media querries

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

Now I mostly use ems and rems, but I think it's still complicated to me in the way that I dont know the actual size of element. Like for my eye I know how looks 24px but I can say the same about 2em because it's different if your base font-size not the same.

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

I get confused at the begining, because in the last article there was grids. I though I should use grids to make this layout, but for me it's easier with flex-box and I did it with it.

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

Flex-boxes is my love