Oh shit, I didn't even know about shorthand notation. That saves me a line break in my Medium writeup. THANK YOU. Thanks for the in-depth critique! I'd be worried if you saw the code I wrote for a living.
I enjoy the learning and discovery that goes with CSS grid, if I look at my first attempts I realise how I wasn't thinking straight then...
How is your 3D modelling?
If done in 3D and made web possible with ThreeJS then the world is your oyster. You could model the frame, the reflection on the glass, maybe even add a gentle breeze. The strips would be low polygon count squares with the vertex normals set to smooth shading but fully 'cut-able'.
Add some physics engine and you could have the cut pieces of paper behave like confetti.
As for a starting point: