<!DOCTYPE html>
<title>Tests that @position-try rules are reordered by cascade layers</title>
<link rel="help" href="https://drafts.csswg.org/css-anchor-1/#fallback-rule">
<link rel="help" href="https://www.w3.org/TR/css-cascade-5/#layering">
<link rel="author" href="mailto:[email protected]">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
body { margin: 0; }
#anchor {
width: 100px;
height: 100px;
margin-left: 200px;
margin-top: 200px;
color: orange;
anchor-name: --a;
}
.target {
position: absolute;
width: 100px;
height: 100px;
color: lime;
position-try-fallbacks: --fallback;
left: 999999px; /* force fallback */
}
</style>
<div id="anchor"></div>
<script>
function createTargetWithStyle(test, style) {
let styleElement = document.createElement('style');
styleElement.textContent = style;
let target = document.createElement('div');
target.classList.add('target');
test.add_cleanup(() => {
styleElement.remove();
target.remove();
});
document.head.appendChild(styleElement);
document.body.appendChild(target);
return target;
}
test(t => {
const target = createTargetWithStyle(t, `
@position-try --fallback {
left: auto;
right: anchor(--a left);
}
@position-try --fallback {
left: anchor(--a right);
}
`);
assert_equals(target.offsetLeft, 300);
}, 'When in the same layer, the last rule of each name wins');
test(t => {
const target = createTargetWithStyle(t, `
@position-try --fallback {
left: auto;
bottom: anchor(--a top);
}
@layer {
@position-try --fallback {
left: auto;
top: anchor(--a bottom);
}
}
`);
assert_equals(target.offsetTop, 100);
}, 'When in different layers, the rule of each name in the highest layer wins');
</script>
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