<!DOCTYPE html>
<title>@container: scroll-state(snapped) changed after scroll</title>
<link rel="help" href="https://drafts.csswg.org/css-conditional-5/#container-rule">
<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>
:root {
scroll-snap-type: block mandatory;
}
body {
margin: 0;
}
#filler {
height: 10000px;
}
.snapped {
container-type: scroll-state;
scroll-snap-align: start;
width: 100px;
height: 100px;
margin-bottom: 100px;
background: teal;
}
@container scroll-state(snapped: block) {
span { --snapped: yes }
}
</style>
<div class="snapped">
<span id="target1"></span>
</div>
<div class="snapped">
<span id="target2"></span>
</div>
<div id="filler"></div>
<script>
setup(() => assert_implements_container_queries());
promise_test(async t => {
await waitForAnimationFrames(2);
assert_equals(getComputedStyle(target1).getPropertyValue("--snapped"), "yes");
assert_equals(getComputedStyle(target2).getPropertyValue("--snapped"), "");
assert_equals(document.documentElement.scrollTop, 0);
}, "Check that scroll-state(snapped: block) matches on #target1 before scroll");
promise_test(async t => {
document.documentElement.scrollTop = 300;
await waitForAnimationFrames(2);
assert_equals(getComputedStyle(target1).getPropertyValue("--snapped"), "");
assert_equals(getComputedStyle(target2).getPropertyValue("--snapped"), "yes");
assert_equals(document.documentElement.scrollTop, 200);
}, "Check that scroll-state(snapped: block) matches on #target2 after scroll");
</script>