title: Fixed navigation add class depend of section
body: <p>I need to add class to header depend of section its by. here is my code</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>.navigation {
      position: fixed;
      background: white;
      width: 400px;
      height:15px;
      border: 1px solid #000;
      color: orange;
  }
  
  section {
      display: block;
      width: 100%;
      height:200px;
  }
  
  .first-section {
      background-color: black;
  }
  
  .second-section {
      background-color: white;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div id="nav" class="navigation"&gt;menu&lt;/div&gt;
  
  &lt;section class="first-section" id="a"&gt;&lt;/section&gt;
  &lt;section class="second-section"  id="b"&gt;&lt;/section&gt;
  &lt;section class="third-section" id="c"&gt;&lt;/section&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>I guess I need some jQuery code to add class to <code>.navigation</code> when its bring to <code>.second-section</code> <a href="https://jsfiddle.net/vachos/m03s32pL/12/" rel="nofollow noreferrer">JSFiddle link</a>  </p>