title: Which type of quotes we should use in css background url ("....")? Single, double or no quote needed?
body: <p>this</p>
  
  <pre><code>background:url(http://url);
  </code></pre>
  
  <p>this</p>
  
  <pre><code>background:url("http://url");
  </code></pre>
  
  <p>or this</p>
  
  <pre><code>background:url('http://url');
  </code></pre>