title: CSS3 blur overlay
body: <p>I am trying to create overlay that would cover whole site page and blur everything that is behind it. I searched for solution, tried multiple versions with CSS3 blur filter, but without success. Main problem is when body tag have background, it is not blurred.</p>
  
  <p>Toy example:</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>body
  {
    background: url("https://upload.wikimedia.org/wikipedia/commons/8/8a/Too-cute-doggone-it-video-playlist.jpg");
     
  }
  
  h1
  {
    text-align: center;
  }
  
  #overlay
  {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    background: rgba(0, 0, 0, 0.5);
    -webkit-filter: blur(10px);
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;html&gt;
  &lt;head&gt;&lt;/head&gt;
  &lt;body&gt;
    &lt;h1&gt;
       Text
    &lt;/h1&gt;
    
    &lt;div id="overlay"&gt;
        overlay
    &lt;/div&gt;
  &lt;/body&gt;
  &lt;/html&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>I want to try to blur everything behind overlay div.
  If I add blur to h1 (or if I wrap it inside other div and add blur on that div) I could reach near solution, but without blur of background.</p>
  
  <p>Is there any solution that could fulfil all requests?  </p>
  
  <p>Idea is to create a JavaScript file, that would do this programatically so that I could use on multiple pages.</p>