Cut-paper torus
Geometry
The ring is rebuilt as a stack of L paper cut-outs, drawn back to front, each an annulus between an outer ellipse Ro and an inner ellipse Ri, squashed vertically by q.
layer k: rotate(k·Δθ) · scale(1 + k·Δs) · offset k·(cos25°, sin25°)·offset
Every layer shifts a little further along a fixed 25° direction, turns a fraction of a degree, and grows slightly, so the pile reads as a sheet stack seen at a shallow angle rather than as repeated outlines. The deepest layer is the darkest: its colour is the base tone scaled by 1 − colourStep/100 · (L−1−k)/(L−1), rising to the full base colour on top.
Each sheet drops a blurred copy of itself 4 px right and 6 px down in rgba(0,0,0,0.28), which is what separates the layers and gives the flat shapes their depth.