<!DOCTYPE html>
<title>CSS Anchor Positioning Test: Effects from @position-try in CSS Typed OM</title>
<link rel="help" href="https://drafts.csswg.org/css-anchor-position-1/#fallback-apply">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
@position-try --pt {
left: anchor(right);
top: 50px;
width: anchor-size(width);
height: 40px;
}
#cb {
position: relative;
width: 100px;
height: 100px;
border: 1px solid black;
}
#anchor {
position: absolute;
left: 10px;
top: 10px;
width: 20px;
height: 20px;
background: coral;
anchor-name: --a;
}
#target {
position: absolute;
background: skyblue;
position-anchor: --a;
left: 9999px; /* force overflow */
position-try-fallbacks: --pt;
}
</style>
<div id=cb>
<div id=anchor></div>
<div id=target></div>
</div>
<script>
function assert_unit_value(actual, expected) {
assert_true(actual instanceof CSSUnitValue);
assert_true(expected instanceof CSSUnitValue);
assert_equals(actual.value, expected.value);
assert_equals(actual.unit, expected.unit);
}
test(() => {
assert_unit_value(target.computedStyleMap().get('left'), CSS.px(30));
assert_unit_value(target.computedStyleMap().get('top'), CSS.px(50));
assert_unit_value(target.computedStyleMap().get('width'), CSS.px(20));
assert_unit_value(target.computedStyleMap().get('height'), CSS.px(40));
}, 'Effects of position-try-fallbacks are visible in the computed values');
</script>