<!DOCTYPE html> <!-- Any copyright is dedicated to the Public Domain. - http://creativecommons.org/publicdomain/zero/1.0/ --> <html class="reftest-wait"> <script> function runTest() { // Remove first <summary> from <details>. Second <summary> should be used. var details = document.getElementById("details"); var summary = document.getElementById("summary"); details.removeChild(summary); document.documentElement.removeAttribute("class"); } </script> <body onload="runTest();"> <details open id="details"> <summary>Summary</summary> <summary id="summary">Removed Summary</summary> <p>This is the details.</p> </details> </body> </html>