title: How to fill svg when scrolling
body: <p>I have svg line:</p>
  
  <pre><code>&lt;svg class="filling" width="500" height="10" version="1.1" xmlns="http://www.w3.org/2000/svg"&gt;
      &lt;path data-over-line="" d="M90,5 L500,5" stroke="#e2e2e2" fill="transparent" stroke-width="4" style="stroke-dashoffset: 0px;"&gt;&lt;/path&gt;
  &lt;/svg&gt;
  </code></pre>
  
  <p>I need when scroll the page it is gradually filled with a different color. How to do it?</p>