| <!DOCTYPE html> |
| <title>CSS Test: `will-change: z-index`</title> |
| <link rel="author" title="Oriol Brufau" href="obrufau@igalia.com"> |
| <link rel="help" href="https://www.w3.org/TR/css-will-change/#valdef-will-change-custom-ident"> |
| <link rel="help" href="https://www.w3.org/TR/css-flexbox-1/#painting"> |
| <link rel="help" href="https://github.com/w3c/csswg-drafts/issues/11827"> |
| <link rel="match" href="../reference/ref-filled-green-100px-square.xht"> |
| <meta name="assert" content=" |
| `will-change: z-index` establishes a stacking context on a flex item. |
| "> |
| <style> |
| .test { |
| will-change: z-index; |
| width: 100px; |
| background: red; |
| } |
| .test::before { |
| content: ""; |
| display: block; |
| position: relative; |
| z-index: -1; |
| height: 100px; |
| background: green; |
| } |
| </style> |
| <p>Test passes if there is a filled green square and <strong>no red</strong>.</p> |
| <div style="display: flex"> |
| <div class="test"></div> |
| </div> |
