title: make the scrollbar css visible in the web page
body: <p>I'am trying to implement a scrollbar and preventing content from moving when the scrollbar appear 
  i found a solution that make the page scrollable but the scrollbar is invisible
  how can i make it visible in the page.
  this is my first solution:</p>
  
  <pre><code>mat-sidenav-content{
    width: -webkit-fill-available;
    &amp;::-webkit-scrollbar {
      width: 0px;
  
  }
  }
  </code></pre>