Bootstrap button text word wrap

<html>
<head>
<title>Bootstrap Grid</title>
<!-- Latest compiled and minified CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap.min.css">

<!-- Optional theme -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap-theme.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<!-- Latest compiled and minified JavaScript -->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/js/bootstrap.min.js"></script>
<style>
.btn{
white-space:normal !important;
word-wrap: break-word; 
max-width:150px;
}
</style>
</head>
<body>
<div class="container">
 <button type='button' class='btn primary'>This is simple button with long text....</button>
</div>
</body>
</html>