<!-- ... -->
<div class="card border-0 border-top border-success">
<div class="card-header">
<h6 class="mb-0">Top custom border</h6>
</div>
<div class="card-body">
Custom color of the <strong>top</strong> border. Use optional <code>.rounded-top-0</code> class to remove rounded top corners
</div>
</div>