| <!DOCTYPE html> |
| <meta charset="utf-8"> |
| <title>CSS transforms: Creating containing block for fixed positioned elements</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-transforms-2/#perspective-property"> |
| <link rel="match" href="containing-block-dynamic-1-ref.html"> |
| <meta name="assert" content="It also establishes a containing block (somewhat similar to position: relative), just like the transform property does."> |
| <meta name="flags" content="dom"> |
| <style> |
| html, body { margin: 0; padding: 0 } |
| #changeperspective { |
| position: absolute; |
| top: 100px; |
| left: 100px; |
| } |
| |
| #abscovered { |
| position: absolute; |
| top: 50px; |
| left: 50px; |
| background: red; |
| height: 100px; |
| width: 100px; |
| } |
| |
| #fixedmoves { |
| position: fixed; |
| top: 50px; |
| left: 50px; |
| background: green; |
| height: 100px; |
| width: 100px; |
| } |
| </style> |
| <body> |
| <div id="changeperspective"> |
| <div id="abscovered"></div> |
| <div id="fixedmoves"></div> |
| </div> |
| <script> |
| var changeperspective = document.getElementById("changeperspective"); |
| var fixedmoves = document.getElementById("fixedmoves"); |
| var causeFlush = fixedmoves.offsetTop; |
| changeperspective.style.perspective = "1000px"; |
| </script> |
| </body> |