Drop Shadow Softness
drop-shadow-softness
The drop-shadow-softness parameter sets how large the light source is, from 0 to 100. It defaults to 50.
0 is a point light — a crisp shadow with the same hard edge all the way along. 100 is a broad light like an overcast sky, where the shadow stays sharp at the contact point and blurs out with distance. This blur-with-distance is what makes a cast shadow read as real rather than as a blurred silhouette.
High softness grows the canvas, because the far end of the shadow spreads wider.
It is read only by drop-shadow-type=cast, and values are clamped to 0-100.
