mask-position CSS property.
Initial value: center
Applies to: All elements. In SVG, it applies to container elements excluding the <defs> element and all graphics elements
Inherit: no
Percentages: refer to size of mask painting area minus size of mask layer image; see text background-position [CSS3BG]
Animatable: as repeatable list of simple list of length, percentage, or calc
Media: visual
Computed value: Consisting of: two keywords representing the origin and two offsets from that origin, each given as an absolute length (if given a <length>), otherwise as a percentage.
CSS Standards
CSS 1
CSS 2
CSS 2.1
CSS 3
No
No
No
Yes