| <!DOCTYPE html> |
| <title>Test that ::backdrop responds to container size changes</title> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <style> |
| :root { |
| color: black; |
| } |
| |
| #container { |
| contain: size layout; |
| width: 200px; |
| height: 40px; |
| } |
| |
| ::backdrop { |
| background-color: black; |
| } |
| |
| @container (min-width: 300px) { |
| ::backdrop { |
| background-color: green; |
| } |
| } |
| </style> |
| <main id=container> |
| <dialog>test</dialog> |
| </main> |
| <script> |
| let dialog = document.querySelector('dialog'); |
| |
| test(function() { |
| try { |
| dialog.showModal(); |
| |
| assert_equals(getComputedStyle(dialog, '::backdrop').backgroundColor, 'rgb(0, 0, 0)'); |
| |
| container.style.width = '300px'; |
| assert_equals(getComputedStyle(dialog, '::backdrop').backgroundColor, 'rgb(0, 128, 0)'); |
| |
| container.style = ''; |
| assert_equals(getComputedStyle(dialog, '::backdrop').backgroundColor, 'rgb(0, 0, 0)'); |
| } finally { |
| dialog.close(); |
| } |
| }, 'Pseudo-element ::backdrop responds to container size changes'); |
| </script> |
