title: CSS current window size
body: <p>I am trying some thing like making the background of the whole body part.</p>
  
  <pre><code>&lt;html&gt;
  &lt;head&gt;&lt;head/&gt;
  &lt;body&gt;
  &lt;div class="wrapper"&gt;&lt;/div&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>in this case how do i get the height and width of the current body cause i show a popup other than that i want to blur the whole background.</p>