mask-border-source

none

No mask border is used.

<image>

Image reference to use for the mask border.

mask-border-source = 
  none     |
  <image>  

<image> = 
  <url>       |
  <gradient>  

<gradient> = 
  <linear-gradient()>            |
  <repeating-linear-gradient()>  |
  <radial-gradient()>            |
  <repeating-radial-gradient()>  

<linear-gradient()> = 
  linear-gradient( [ <angle> | to <side-or-corner> ]? , <color-stop-list> )  

<radial-gradient()> = 
  radial-gradient( [ <ending-shape> || <size> ]? [ at <position> ]? , <color-stop-list> )  

<side-or-corner> = 
  [ left | right ]  ||
  [ top | bottom ]  

<color-stop-list> = 
  <linear-color-stop> , [ <linear-color-hint>? , <linear-color-stop> ]#  

<size> = 
  <extent-keyword>              |
  <length [0,∞]>                |
  <length-percentage [0,∞]>{2}  

<position> = 
  [ left | center | right | top | bottom | start | end | <length-percentage> ]  |
  [ left | center | right | x-start | x-end | <length-percentage> ] [ top | center | bottom | y-start | y-end | <length-percentage> ]  |
  [ center | [ left | right | x-start | x-end ] <length-percentage>? ] && [ center | [ top | bottom | y-start | y-end ] <length-percentage>? ]  |
  [ center | [ start | end ] <length-percentage>? ] [ center | [ start | end ] <length-percentage>? ]  

<linear-color-stop> = 
  <color>               &&
  <length-percentage>?  

<linear-color-hint> = 
  <length-percentage>  

<extent-keyword> = 
  closest-corner   |
  closest-side     |
  farthest-corner  |
  farthest-side    

<length-percentage> = 
  <length>      |
  <percentage>  

<color> = 
  <absolute-color-base>  |
  currentcolor           |
  <system-color>         

<absolute-color-base> = 
  <hex-color>                |
  <absolute-color-function>  |
  <named-color>              |
  transparent                

<absolute-color-function> = 
  <rgb()>    |
  <rgba()>   |
  <hsl()>    |
  <hsla()>   |
  <hwb()>    |
  <lab()>    |
  <lch()>    |
  <oklab()>  |
  <oklch()>  |
  <color()>  

<rgb()> = 
  rgb( [ <percentage> | none ]{3} [ / [ <alpha-value> | none ] ]? )  |
  rgb( [ <number> | none ]{3} [ / [ <alpha-value> | none ] ]? )  

<hsl()> = 
  hsl( [ <hue> | none ] [ <percentage> | none ] [ <percentage> | none ] [ / [ <alpha-value> | none ] ]? )  

<hwb()> = 
  hwb( [ <hue> | none ] [ <percentage> | none ] [ <percentage> | none ] [ / [ <alpha-value> | none ] ]? )  

<lab()> = 
  lab( [ <percentage> | <number> | none ] [ <percentage> | <number> | none ] [ <percentage> | <number> | none ] [ / [ <alpha-value> | none ] ]? )  

<lch()> = 
  lch( [ <percentage> | <number> | none ] [ <percentage> | <number> | none ] [ <hue> | none ] [ / [ <alpha-value> | none ] ]? )  

<oklab()> = 
  oklab( [ <percentage> | <number> | none ] [ <percentage> | <number> | none ] [ <percentage> | <number> | none ] [ / [ <alpha-value> | none ] ]? )  

<oklch()> = 
  oklch( [ <percentage> | <number> | none ] [ <percentage> | <number> | none ] [ <hue> | none ] [ / [ <alpha-value> | none ] ]? )  

<color()> = 
  color( <colorspace-params> [ / [ <alpha-value> | none ] ]? )  

<alpha-value> = 
  <number>      |
  <percentage>  

<hue> = 
  <number>  |
  <angle>   |
  none      

<colorspace-params> = 
  <predefined-rgb-params>  |
  <xyz-params>             

<predefined-rgb-params> = 
  <predefined-rgb> [ <number> | <percentage> | none ]{3}  

<xyz-params> = 
  <xyz-space> [ <number> | none ]{3}  

<predefined-rgb> = 
  srgb          |
  srgb-linear   |
  display-p3    |
  a98-rgb       |
  prophoto-rgb  |
  rec2020       

<xyz-space> = 
  xyz      |
  xyz-d50  |
  xyz-d65  

This property doesn't appear to be supported anywhere yet. When it eventually starts to be supported, it will serve to define the source of the border mask.

mask-border-source: url(image.jpg);

Chromium-based browsers support an outdated version of this property — mask-box-image-source — with a prefix:

-webkit-mask-box-image-source: url(image.jpg);

• mask-border
• mask-border-mode
• mask-border-outset
• mask-border-repeat
• mask-border-width