Sciter version 2.0.2.3 contains support of shadows in CSS, see the ‘box-shadow’ property specification.

UI and frontend software design and consulting since 1991
Sciter version 2.0.2.3 contains support of shadows in CSS, see the ‘box-shadow’ property specification.
Did you make it using Direct 2D or had to make the complete algorithm?
Shadow in my implementation is an expandable bitmap similar to background-repeat:expand;
It is rendered using D2D primitives but generated in code and cached for later use.