Makes a matched set of small, medium and large layered box-shadows as custom properties so every shadow on a page shares one light source.

A tool by Josh W. Comeau that builds a set of layered box-shadow values at three elevations: low, medium and high. Each level stacks several shadows (three, four and eight layers in the default output) to look softer and more realistic than a single shadow.
You adjust sliders called Oomph and Crispy, move the light source, set the background colour, choose a resolution and optionally tint the shadows to match the background.
The output is a :root block of custom properties: --shadow-color plus --shadow-elevation-low, -medium and -high, which you copy into your stylesheet and use as box-shadow values.