Constant LIGHT_SHADOW_SCALE 

pub const LIGHT_SHADOW_SCALE: f32 = _; // 0.368421048f32

How much of the dark material’s floating shadow a light material keeps: the design language’s light floating layer (alpha 0.14) over the dark one (0.38).

A drop shadow is black in either polarity, so equal alpha does not buy equal weight: the same wash that a dark ground swallows whole lands hard on a pale one.