<!DOCTYPE html> <meta charset="utf-8"> <title>CSS will-change: 'will-change: perspective' creates a stacking context</title> <link rel="author" title="L. David Baron" href="https://dbaron.org/"> <link rel="author" title="Mozilla" href="http://www.mozilla.org/"> <link rel="help" href="https://drafts.csswg.org/css-will-change-1/#will-change"> <link rel="help" href="http://www.w3.org/TR/css3-transforms/#perspective-property"> <link rel="match" href="green-square-100-by-100-ref.html"> <meta name="assert" content="If any non-initial value of a property would create a stacking context on the element, specifying that property in will-change must create a stacking context on the element."> <style> html, body { margin: 0; padding: 0; } div { width: 100px; height: 100px } #wc { will-change: perspective; background: red } #child { position: absolute; top: 0; left: 0; z-index: -1; background: green } </style> <body> <div id="wc"> <div id="child"> </div> </div> </body>