Need help creating a responsive card deck with fixed-width cards in Bootstrap 4. I've included the code below, but it's not rendering responsively. Can anyone assist?
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<div class="card-deck">
<div class="card col-lg-2 col-md-3 col-sm-4 col-6" style="max-width: 12rem;">
<div class="card-body">
<h4 class="card-title">Title 1</h4>
<p>Small text here</p>
<small class="text-muted">3 mins ago</small>
</div>
</div>
<div class="card col-lg-2 col-md-3 col-sm-4 col-6" style="max-width: 12rem;">
<div class="card-body">
<h4 class="card-title">Title 2</h4>
<p>Small text here</p>
<small class="text-muted">3 mins ago</small>
</div>
</div>
<div class="card col-lg-2 col-md-3 col-sm-4 col-6" style="max-width: 12rem;">
<div class="card-body">
<h4 class="card-title">Title 3</h4>
<p>Small text here</p>
<small class="text-muted">3 mins ago</small>
</div>
</div>
<div class="card col-lg-2 col-md-3 col-sm-4 col-6" style="max-width: 12rem;">
<div class="card-body">
<h4 class="card-title">Title 4</h4>
<p>Small text here</p>
<small class="text-muted">3 mins ago</small>
</div>
</div>