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Test Info: Warnings
- This test has a WPT meta file that expects 2 subtest issues.
 - This WPT test may be referenced by the following Test IDs:
            
- /css/css-anchor-position/container-queries/anchored-fallback-scroll.html - WPT Dashboard Interop Dashboard
 
 
<!DOCTYPE html>
<title>CSS Conditional Test: @container anchored(fallback) changes on scroll</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/css/css-conditional/container-queries/support/cq-testcommon.js"></script>
<script src="/css/css-transitions/support/helper.js"></script>
<style>
  body { margin: 0; }
  #anchor {
    anchor-name: --a;
    margin-top: 100px;
    width: 100px;
    height: 100px;
  }
  #anchored {
    position: fixed;
    position-anchor: --a;
    position-area: top;
    position-try-fallbacks: flip-block;
    width: 100px;
    height: 100px;
    container-type: anchored;
  }
  @container anchored(fallback: none) {
    #t1 { --fallback: no; }
  }
  @container anchored(fallback: flip-block) {
    #t1 { --fallback: yes; }
  }
</style>
<div id="anchor"></div>
<div id="anchored">
  <div id="t1"></div>
</div>
<div style="height:3000px">XXX</div>
<script>
  promise_test(async t => {
    await waitForAnimationFrames(2);
    assert_equals(document.documentElement.scrollTop, 0);
    assert_equals(getComputedStyle(t1).getPropertyValue("--fallback"), "no");
  }, "@container anchored() without applied fallback at initial scroll position");
  promise_test(async t => {
    document.documentElement.scrollTop = 100;
    await waitForAnimationFrames(2);
    assert_equals(getComputedStyle(t1).getPropertyValue("--fallback"), "yes");
  }, "@container anchored() applies fallback after scrolling down");
</script>