HTML/CSS ?

You should look at laying our your cards using Grid Template Areas this makes it easy to transition between the one column mobile layout and the 3 column desktop one it also allows a good mid transition of 2 columns with 2 cards each to make better use of the space in the browser for the mid sized screens

Hello Thibaud. I have a tip.

Try forming three columns by adding the two middle boxes inside another element "e.g. a flexbox div". Then just adjust the spacing.

It's a simple way to get closer to the original design... without changing too much what you've built.

Hope this helps. Keep coding!