<!DOCTYPE html>
<title>position:sticky elements should not affect the flow position of other elements</title>
<link rel="help" href="https://www.w3.org/TR/css-position-3/#sticky-pos" />
<meta name="assert" content="This test checks that position:sticky elements do not affect the flow position of other elements" />
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
.scroller {
position: relative;
height: 200px;
width: 100px;
overflow: scroll;
}
#sticky {
background-color: green;
position: sticky;
top: 150px;
}
#before {
background-color: fuchsia;
}
#after {
background-color: orange;
}
.box {
height: 50px;
width: 50px;
}
.padding {
height: 500px;
}
</style>
<div class="scroller">
<div id="before" class="box"></div>
<div id="sticky" class="box"></div>
<div id="after" class="box"></div>
<div class="padding"></div>
</div>
<script>
test(() => {
// The sticky element is pushed to be stuck 150 pixels from the top.
assert_equals(sticky.offsetTop, 150);
// Neither 'before' or 'after' should be affected by the change in the sticky
// element's location.
assert_equals(before.offsetTop, 0);
assert_equals(after.offsetTop, before.clientHeight + sticky.clientHeight);
}, 'sticky offset should not affect the position of other elements.');
</script>