4-card section – HTML/CSS using BEM & flexbox, + keyframes

Hi there 👋 Working my way through "newbie" challenges and trying to practice something new when possible! For this challenge, I've used flexbox; and the different positioning of cards in the desktop version got me thinking for some time. I've almost swapped it to the grid display, but went with transform in the end on selected cards with some flexbox tidying-up. As an extra touch, I've practiced @keyframes: I wanted to have each card appear separately and retain the style from the starting point. I think it works nicely, and I have +1 concept in my bag 🎉

Any feedback – let me know, super happy to hear any pointers on how to improve my code 🙌