eudo-states, namely <code>:hover</code>.  This link will show an
underline via <code>text-decoration: underline</code> (tdu) only when the user agent is capable of hovering and actually <em>is</em> hovering.
Otherwise, there is no text decoration:</p>
<pre><code>&lt;a href=&quot;#&quot; class=&quot;tdn hover-tdu&quot;&gt;
  Click Me, or Just Hang Around
&lt;/a&gt;
</code></pre>
<p>It’s the equivalent of this:</p>
<pre><code>a {
  text-decoration: none;
}
@media(hover: hover) {
  a:hover {
    text-decorat