<style>
   #x13 { letter-spacing: 1em; text-wrap: pretty;direction: ltr;}
   *:first-child, style {margin-right: 999px; display: table-header-group;box-align: baseline;}
   *:last-child { font-family: system-ui;}
</style>
<script>
   function main() {
   try { x21.appendChild(document.createTextNode("A { Awebkit-align-self: AAAA;tab-size: 1em;-webkit-line-clamp: 16;-webkit-hyphenate-character: auto }")); } catch (e) { }
   }
   if (window.testRunner)
       testRunner.dumpAsText();
</script>
<body onload="main()">
   <summary id="x13" contenteditable="true">
   <style id="x21"></style>
AAAAAAAAAAAAAAAAAAAA
</body>
This test passes if it doesn't crash.