mask-border-outset

The mask-border-outset CSS property specifies the distance by which an element's mask border is set out from its border box.

Syntax

/* <length> value */
mask-border-outset: 1rem;

/* <number> value */
mask-border-outset: 1.5;

/* vertical | horizontal */
mask-border-outset: 1 1.2;

/* top | horizontal | bottom */
mask-border-outset: 30px 2 45px;

/* top | right | bottom | left */
mask-border-outset: 7px 12px 14px 5px;

/* Global values */
mask-border-outset: inherit;
mask-border-outset: initial;
mask-border-outset: unset;

The mask-border-outset property may be specified as one, two, three, or four values. Each value is a <length> or <number>. Negative values are invalid.

• When one value is specified, it applies the same outset to all four sides.
• When two values are specified, the first outset applies to the top and bottom, the second to the left and right.
• When three values are specified, the first outset applies to the top, the second to the left and right, the third to the bottom.
• When four values are specified, the outsets apply to the top, right, bottom, and left in that order (clockwise).

Values

<length>

The size of the mask border outset as a dimension.

<number>

The size of the mask border outset as a multiple of the corresponding border-width.

Formal syntax

[ <length> | <number> ]{1,4}

Specifications

Browser compatibility

TBD