JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta/css/bootstrap.min.css">
<div class="card">
  <div class="card-header">
    Featured
  </div>
  <div class="card-body">
    <h4 class="card-title">Special title treatment</h4>
    <p class="card-text">With supporting text below as a natural lead-in to additional content.</p>
    <a href="#" class="btn btn-primary">Go somewhere</a>
  </div>
</div>

CSS

.card-header {
    height: 50px;
    background-color: grey;
    border-bottom-color: #fff;
    border-top: none;
    border-radius: 0;
}

.card-header:first-child {
  border-radius: 0;
}