title: Transparency mystery: iframe not transparent in Chrome&IE but Firefox
body: <p>I have a simple scenario:</p>
  
  <p><a href="http://jsfiddle.net/akosk/t2KvE/8/" rel="nofollow">http://jsfiddle.net/akosk/t2KvE/8/</a></p>
  
  <p>HTML</p>
  
  <pre><code>&lt;div id='base'&gt;
      &lt;iframe id="myFrame" src="about:blank" frameborder="0" allowTransparency="true"&gt;&lt;/iframe&gt;    
  &lt;/div&gt;
  
  &lt;script id="content" type="text/html"&gt;
      &lt;html&gt;
          &lt;head&gt;
              &lt;link rel="stylesheet" href="http://netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css"/&gt;
          &lt;/head&gt;
          &lt;body&gt;                                       
              &lt;h2&gt;Lorem ipsum dolor sit amet, consectetur adipisicing elit. Possimus architecto quasi deleniti eius praesentium non officia culpa corporis officiis perferendis laudantium placeat excepturi. Voluptatum fuga mollitia reiciendis non aliquam dolorem!&lt;/h2&gt;              
          &lt;/body&gt;
      &lt;/html&gt;
  &lt;/script&gt;
  </code></pre>
  
  <p>JS</p>
  
  <pre><code>    var myFrame = $("#myFrame");
      var content = $("#content").html();
      myFrame.contents().find('html').html(content);
  </code></pre>
  
  <p>CSS</p>
  
  <pre><code>iframe {
      z-index:0;
      height:100px;
  }
  #base {
      background-color:red;
      height:100px;
      z-index:-1;
  }
  </code></pre>
  
  <p>In Chrome &amp; IE <strong>the background color</strong> of iframe is <strong>white instead of the wrapper's color (red)</strong>. In Firefox it works fine.</p>
  
  <p><strong>Additionally</strong> when inspecting element in Chrome <strong>no HEAD and BODY</strong> nodes in iframe.</p>
  
  <p><strong>When I remove the css (bootstrap) then everything works fine.</strong>
  Somehow if I write anything into HEAD (fe. any css!) the transparency not work and HEAD/BODY tags disappears.</p>
  
  <p>(I tried with * {background-color:transparent} in iframe also without success. I guess the problem is something else)</p>
  
  <p>It's a huge mystery for me. </p>
  
  <p>Can anyone help me?</p>