examples/slim-stp/templates/layout.html.twig
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>{% block title %}{% endblock %}</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" integrity="sha384-1q8mTJOASx8j1Au+a5WDVnPi2lkFfwwEAa8hDDdjZlpLegxhjVME1fgjWPGmkzs7" crossorigin="anonymous">
{% block head %}{% endblock %}
</head>
<body>
<div class="container">
<div class="row">
<div class="col-md-6 col-md-offset-3">
<div class="page-header">
<h1>{{ block('title') }}</h1>
</div>
{% block body %}{% endblock %}
</div>
</div>
</div>
{% block scripts %}{% endblock %}
</body>
</html>