Try adding this PHP Snippet to your site:
add_filter( 'body_class', function( $classes ) {
global $generate_elements;
foreach ( $generate_elements as $element => $data ) {
$element_title = 'gp-elem-' . strtolower(str_replace(' ', '-', get_the_title( $data['id'] ) ));
$classes[] = $element_title;
}
return $classes;
});
In the body tag it will print a class like so: gp-elem-{elements-title} for each element on the page.
For example i create an element titled: menu-light
Then it will print a class: gp-elem-menu-light that you can use in your CSS.