Bootstrap -btn-group

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/css/bootstrap.min.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.3/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/js/bootstrap.min.js"></script>
<div class="btn-group" role="group" aria-label="Basic example">
  <button type="button" class="btn btn-primary">Left</button>
  <button type="button" class="btn btn-success">Middle</button>
  <button type="button" class="btn btn-danger">Right</button>
</div>
<br>
<div class="btn-group" role="group" aria-label="Basic example">
  <button type="button" class="btn btn-success">one</button>
 

</div>

CSS

.container {
    background: #f0f0f0;
}