<div id="progressbar">
      <div></div>
    </div>
<style type="text/css">
   #progressbar {
      background-color: black;
      border-radius: 13px; /* (height of inner div) / 2 + padding */
      padding: 3px;
    }
    
    #progressbar > div {
       background-color: orange;
       width: 40%; /* Adjust with JavaScript */
       height: 20px;
       border-radius: 10px;
    } 
</style>