HTML Code

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>append link</title>
</head>
<body>
  <p id="demo">Styled by injected CSS</p>
  <pre id="out"></pre>
  <script>
    var link = document.createElement("link");
    link.rel = "stylesheet";
    link.href = "data:text/css,#demo{color:teal;font-weight:bold;}";
    document.head.appendChild(link);
    document.getElementById("out").textContent =
      "stylesheets: " + document.head.querySelectorAll('link[rel="stylesheet"]').length;
  </script>
</body>
</html>

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