Want to apply an Enfold Stylesheet to a third-party plugin

I am using a third-party plugin that creates a custom page that contains a checkout iFrame for WePAY. Unfortunately, it doesn’t style the page based on the theme. I have added code to the functions.php that has allowed me to add my logo to the page:

if ( ! function_exists( ‘mycred_buyCRED_custom_styling’ ) ) :
add_action( ‘mycred_buy_cred_page_header’, ‘mycred_buyCRED_custom_styling’ );
function mycred_buyCRED_custom_styling() {
echo ‘
<style type=”text/css”>
html { background-color: rgb(34, 34, 34); }
body { width: auto; height: inherit; margin: 0; padding: 120px 0 0 0; overflow: hidden; }
body { background-image: url(“http://www.crewnami.com/wp-content/uploads/2013/10/Crewnami_Logo_V3.png&#8221;); background-position: top center; background-repeat: no-repeat; }
body > img { display: none; }
body > p { position: absolute; top: 24px; left: 24px; margin: 0; padding: 0;
</style>’;
}
endif

However, I would like it to look like the rest of the site. Unfortunately, that is above my pay grade. I would appreciate any help that could be provided.

THANK YOU