app/views/layouts/application.html.erb
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<title>login.gov :: Service Provider</title>
<%= stylesheet_link_tag 'application', media: 'all', 'data-turbolinks-track' => true %>
<%= csrf_meta_tags %>
</head>
<body>
<%== yield %>
<%= javascript_include_tag 'application', media: 'all' %>
</body>
</html>