title: Nested divs bigger than parent div
body: <p>I am using CSS to skin a scroll bar that is created using JavaScript.</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>.scrollbar-track{
      background: black;
      height: 10px;
  }
   
  .scrollbar-thumb{
      cursor: default;
      border: 1px red solid;
      width: 50px;
      padding: 0;
  }
  
  .scrollbar-thumb-first{
      display: inline-block;
      background: green;
      width: 5px;
      height: 10px;
  }
   
  .scrollbar-thumb-middle{
      display: inline-block;
      background: red;
      height: 10px;
      width: 20px;
  }
   
  .scrollbar-thumb-last{
      display: inline-block;
      background: blue;
      width: 5px;
      height: 10px;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="scrollbar"&gt;
      &lt;div class="scrollbar-track" style="width: 970px;"&gt;
          &lt;div class="scrollbar-thumb"&gt;
              &lt;span class="scrollbar-thumb-first"&gt;&lt;/span&gt;
              &lt;span class="scrollbar-thumb-middle"&gt;&lt;/span&gt;
              &lt;span class="scrollbar-thumb-last"&gt;&lt;/span&gt;
          &lt;/div&gt;
      &lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>And this is the fiddle: <a href="http://jsfiddle.net/w27wM/8/" rel="nofollow noreferrer">http://jsfiddle.net/w27wM/8/</a></p>
  
  <p>Why is the inner div somehow larger than the parent div? Even with margin and paddings set to 0, the issue still remain.</p>