<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>CSS Masking: mask-image: mask layer image</title> <link rel="author" title="CJ Ku" href="mailto:cku@mozilla.com"> <link rel="author" title="Mozilla" href="https://www.mozilla.org"> <link rel="help" href="https://www.w3.org/TR/css-masking-1/#the-mask-image"> <link rel="match" href="mask-image-1-ref.html"> <meta name="assert" content="Test checks whether treat unresolvable mask as no-mask for a SVG element embedded in HTML document."> </head> <body> <svg width="100" height="100"> <rect x="0" y="0" width="100" height="50" fill="purple" mask="url(#foo)"/> </svg> </body> </html>