se unexpected behavior. While <code>id</code> attribute values containing a
hyphen are still available as property names, these cannot be referenced as
global JavaScript variables.</p>

<pre><code class="language-html bad">&lt;!-- Not recommended: `window.userProfile` will resolve to reference the &lt;div&gt; node --&gt;
&lt;div id="userProfile"&gt;&lt;/div&gt;
</code></pre>

<pre><code class="language-html good">&lt;!-- Recommended: `id` attribute is required and its value includes a hyphen --&gt;
&lt;div 