mask-origin

The mask-origin CSS property sets the origin of a mask. This property determines the mask positioning area: the area within which a mask image is positioned. HTML elements can have masks contained within their content border box, padding box, or content box, whereas SVG elements (which don’t have the associated CSS layout boxes) can have masks contained inside their fill, stroke, or view box. For elements rendered as multiple boxes, such as a <span> of text that spans more than one line, the mask-origin property specifies which boxes the box-decoration-break property operates on to determine the mask positioning area.

Syntax example: mask-origin: content-box;