Usage: {{body_class}}
Description
{{body_class}} – outputs dynamic CSS classes intended for the <body> tag in your default.hbs or other layout file, and is useful for targeting specific pages (or contexts) with styles.
The {{body_class}} helper outputs different classes on different pages, depending on what context the page belongs to. For example the home page will get the class .home-template, but a single post page would get .post-template.
Examples
default.hbs
<html>
<head>...</head>
<body class="">
...
...
</body>
</html>