I wrote something a bit like this years ago as an experimental portfolio site... a sort of responsive engine managing flat "cards" with CSS shadow cues for depth. (The responsive aspects are all JS on a loop that tweens everything). Ever since Photoshop released drop shadows on the world, I've generally thought that their overuse was a way to mask bad design, but I thought it was interesting at the time to see how far you could get using only drop shadows. Note: This site hasn't been updated in a decade. Not made for dark mode.

https://thestrikeagency.com