<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>CSS Masking: mask-size: mask layer size</title> <link rel="author" title="Astley Chen" href="mailto:aschen@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-size"> <link rel="match" href="mask-size-contain-ref.html"> <meta name="assert" content="Test checks whether sizing mask layer works correctly or not."> <style type="text/css"> div { width: 64px; height: 128px; } #outer { border: 10px solid black; } #inner { background-color: purple; mask-image: url(support/50x50-opaque-blue.svg); mask-repeat: no-repeat; mask-position: left top; mask-size: contain; } </style> </head> <body> <div id="outer"> <div id="inner"></div> </div> </body> </html>