<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<!------ Include the above in your HEAD tag ---------->
<section class="fis-404">
<div class="content-width">
<div class="error404">
<p>Oops!</p>
</div>
<h2>Website is under maintance</h2>
<p>We're sorry, Website is under Maintaince. Our developers are working on it.</p>
<div class="btn-container">
<a class="btn-secondary-green-on-white" href="#">Reach out to us</a>
</div>
</div>
</section>