{{ background }} format AND avatar path

brower rendered the background css style in HTML file

BEFORE:
<pre><code class="language-html">
<style type="text/css">body {background-image:url(
      /images/
    
      bg.jpg
    
  
    );}</style>
<code></pre>


AFTER:
<pre><code class="language-html">
<style type="text/css">body {background-image:url(/images/bg.jpg);}</style>
</code></pre>

Yes , it is what I want to explained.