Variable SELECTION_SHADOW`Const`

SELECTION_SHADOW: "1px 1px 2px 2px var(--sxl-color-shadow, rgba(0, 0, 0, 0.15))" = '1px 1px 2px 2px var(--sxl-color-shadow, rgba(0, 0, 0, 0.15))'

The shadow under a selected movable's frame; content that shades itself draws the same along its outline.