<!DOCTYPE html>
<title>CSS Anchor Positioning: <'position-area'> value</title>
<link rel="help" href="https://drafts.csswg.org/css-anchor-position-1/#position-try-fallbacks">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
#cb {
position: relative;
width: 200px;
height: 200px;
border: 1px solid black;
}
#anchor {
position: absolute;
left: 100px;
top: 100px;
width: 80px;
height: 80px;
background-color: tomato;
anchor-name: --a;
}
#target, #ref {
position: absolute;
width: 40px;
height: 40px;
background-color: skyblue;
position-area: bottom right;
position-anchor: --a;
}
#ref {
background-color: seagreen;
}
</style>
<style id=style>
</style>
<div id=cb>
<div id=anchor></div>
<div id=target></div>
<div id=ref></div>
</div>
<script>
// Test that a given <'position-area'> produces the same result as a reference
// element that is styled with an position-area declaration directly.
function test_position_area_fn(position_area) {
test((t) => {
t.add_cleanup(() => {
style.textContent = '';
});
style.textContent = `
#target {
position-try-fallbacks: ${position_area};
}
#ref {
position-area: ${position_area};
}
`;
assert_equals(target.offsetLeft, ref.offsetLeft, 'offsetLeft');
assert_equals(target.offsetTop, ref.offsetTop, 'offsetTop');
}, `${position_area}`);
}
test_position_area_fn('top left');
test_position_area_fn('span-top left');
test_position_area_fn('top span-left');
test_position_area_fn('top center');
test_position_area_fn('left center');
test_position_area_fn('start center');
test_position_area_fn('center start');
</script>
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