<!doctype html>
<meta charset="utf-8">
<title>:has-slotted flattened through multiple slots</title>
<link rel="help" href="https://github.com/w3c/csswg-drafts/pull/10586">
<link rel="match" href="/css/reference/ref-filled-green-100px-square-only.html">
<p>Test passes if there is a filled green square.</p>
<div id="ancestor">
    <template shadowrootmode="open">
        <div id="host"><template shadowrootmode="open">
            <style>
            slot {
                display: block;
                width