| <!DOCTYPE html> |
| <title>CSS Position Absolute: dynamic changes to containing block width</title> |
| <link rel="author" href="mailto:atotic@google.com"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <link rel="help" href="https://www.w3.org/TR/css-position-3/#abs-non-replaced-width"> |
| <meta name="assert" content="abspos descendant responds to containing block size change"> |
| <style> |
| |
| #container { |
| position: relative; |
| width: 50px; |
| height: 100px; |
| background: red; |
| } |
| #target { |
| position: absolute; |
| left: 0; |
| width: 100%; |
| height: 100%; |
| background: green; |
| } |
| </style> |
| <div id="container"> |
| <div style="display:flex;"> |
| <div id="target"></div> |
| </div> |
| </div> |
| <script> |
| document.body.offsetTop; |
| test(() => { |
| document.getElementById("container").style.width = "100px"; |
| assert_equals(document.querySelector("#target").offsetWidth, 100); |
| }, '#target used container width when computing size'); |
| </script> |