Add Post Status to Body Class

You’ll have to use the body_class hook in the functions.php file of your theme in combination with get_post_status() function. Like the following:

add_filter( 'body_class', 'custom_class' );
function custom_class( $classes ) {
    if ( get_post_status() == 'rejected' ) {
        $classes[] = 'rejected';
    }
    return $classes;
}