1 <!DOCTYPE html>
2 <html><head><meta charset="utf-8">
3 <title>CSS will-change: 'will-change: opacity' creates a stacking context</title>
4 <link href="https://dbaron.org/" rel="author" title="L. David Baron">
5 <link href="http://www.mozilla.org/" rel="author" title="Mozilla">
6 <link href="https://drafts.csswg.org/css-will-change-1/#will-change" rel="help">
7 <link href="https://drafts.csswg.org/css-color-3/#transparency" rel="help">
8 <link href="reference/green-square-100-by-100-ref.htm" rel="match">
9 <meta 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." name="assert">
10 <style>
11 html, body { margin: 0; padding: 0; }
12 div { width: 100px; height: 100px }
13 #wc { will-change: opacity; background: red }
14 #child { position: absolute; top: 0; left: 0; z-index: -1; background: green }
15 </style>
16 </head><body>
17 <div id="wc">
18 <div id="child">
19 </div>
20 </div>
21
22 </body></html>