<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>CSS Masking: mask-image: mask layer image</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-image"> <link rel="match" href="mask-image-1-ref.html"> <meta name="assert" content="Test checks whether image as mask layer works correctly or not."> <style type="text/css"> div { background-color: purple; width: 100px; height: 100px; } div.mask-by-png { mask-image: url(support/transparent-100x50-blue-100x50.png); } </style> </head> <body> <div class="mask-by-png"></div> </body> </html>