title: overflow-x also hides overflow-y
body: <p>There are multiple questions named this way, but I didn't find one that applies to my case, so here I am:</p>
  <p>In this snippet:</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>#container:hover {
    overflow-x: hidden;
  }
  
  #container {
    position: relative;
    width: 400px;
    height: 40px;
    background: red;
    margin: 2em;
  }
  
  #child {
    position: absolute;
    bottom: 0;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div id="container"&gt;
    &lt;div id="child"&gt;
      a&lt;br/&gt;
      b&lt;br/&gt;
      hover&lt;br/&gt;
      me
    &lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  <p>You can see that <code>overflow-x</code>, which is applied when you hover the red box, will also hide the overflow-y (at least on Chrome). This is annoying because I have a tooltip that I would like to be able to overflow above the red box, and in the meantime I have a menu that will slide from the right side and that should stay hidden.</p>
  <p>Is this a bug? Is there a workaround?</p>