| <!DOCTYPE html> |
| <title>CSS Values and Units Test: sibling-index() changing value during @keyframes animation</title> |
| <link rel="help" href="https://drafts.csswg.org/css-values-5/#tree-counting"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <style> |
| @keyframes --anim { |
| from { |
| z-index: sibling-index(); |
| } |
| to { |
| z-index: 1; |
| } |
| } |
| #target { |
| animation: --anim 1000s step-end; |
| position: relative; |
| width: 100px; |
| height: 100px; |
| background: red; |
| } |
| #abs { |
| position: absolute; |
| width: 100px; |
| height: 100px; |
| z-index: 3; |
| background: green; |
| } |
| </style> |
| <p>You should see a green square below.</p> |
| <div> |
| <div id="rm"></div> |
| <div id="abs"></div> |
| <div id="target"></div> |
| </div> |
| <script> |
| test(() => { |
| assert_equals(getComputedStyle(target).zIndex, "3"); |
| }, "Initially, the sibling-index() is 3 for #target"); |
| |
| test(() => { |
| rm.remove(); |
| assert_equals(getComputedStyle(target).zIndex, "2"); |
| }, "Removing a preceding sibling of #target reduces the sibling-index()"); |
| |
| </script> |
