Bootstrap 4

by Al Grant

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.2/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.2/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootswatch/3.3.7/flatly/bootstrap.min.css">
<div class="container">

  <div class="flex-column">
    <div>1</div>
    <div>2</div>
    <div>3</div>
  </div>
</div>

CSS

body {
  margin: 10px;
}

div {
  outline: 2px;
}