I have an existing button in a container in a column. I need it to change from its normal position on desktop to be fixed to the bottom of the screen on mobile.
#free-offer-button {
  background-color: #d97b6c;
  border-color: #d97b6c;
  border-radius: 0px;
  color: #ffffff;
  font-size: 18px;
  font-weight: bold;
  padding: 9px 23px;
}<Col xs={{ span: 12, order: 2 }} md={{ span: 6, order: 1 }}>
<h3 id='first-container-header'>Treat your pet (and you).</h3>
<h3>It's on us!</h3>
<br></br>
<p>Treat your pet to a healthy treat for <strong>free</strong> to kick off your Public Goods trial membership.</p>
<p><strong>See what it's like to be a Public Goods member.</strong></p>
<ul>
  <li>Included in your bundle is free 2-week membership that gives you unlimited access to our entire collection of sustainable essentials.</li>
  <li>Take a load off. We make it easy for your to make better choices. Always included: eco-friendly products you can trust.</li>
</ul>
<div className='d-grid mt-5'>
  <Button variant="btn-block" id='free-offer-button'> Claim your free offer</Button>
</div>
</Col>
 
     
     
    