title: Why is ::first-line not working for span like p / div tags?
body: <p>I have the below code :</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>p::first-line {
    color: #ff0000;
    font-variant: small-caps;
  }
  span::first-line {
    color: #ff0000;
    font-variant: small-caps;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;span&gt; This is to check span.This is to check spanThis is to check spanThis     is to check spanThis is to check spanThis is to check spanThis is to check spanThis is to check spanThis is to check spanThis is to check span&lt;/span&gt;
  
  &lt;p&gt;This is to check p.This is to check p.This is to check p.This is to check p.This is to check p.This is to check p.This is to check p.This is to check p.This is to check p.This is to check p.This is to check p.This is to check p.This is to check p.&lt;/p&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>Issue is that the pseudo-element is working for <code>p</code> tag and changed first line to specified color but the same is not working for <code>span</code> tag.</p>