CSS Masking - mask-border-mode Property

The CSS property mask-border-mode, helps you to specify the blending mode that is used in a mask-border.

Possible values

The CSS property mask-border-mode can have one of the following values:

luminance: The mask values are determined by the luminance values of the mask border image.
alpha: The mask values are determined by the alpha values of the mask border image.

All HTML elements. And in case of SVG, it applies to the container element excluding the <defs> element and all graphics elements

mask-border-mode = luminance | alpha

Note: The CSS property mask-border-mode is not supported by any browser yet.