I was unable to download the child theme from within WP as you suggested (couldn’t activate the Child Themes tab). I downloaded it from your website. The functions.php was empty. I used this:

function enqueue_parent_styles() {
$parent_style = ‘parallel-pro-style’;
wp_enqueue_style( $parent_style, get_template_directory_uri() . ‘/style.css’ );
add_action( ‘wp_enqueue_scripts’, ‘enqueue_parent_styles’ );

I am still getting the same problems with the Gallery lightbox and the video section.

Looks like I need to enqueue all the other CSS files as well. When I added magnific-popup.css, the video works. It would be very helpful if you included this in the functions.php of your child theme.

Thank you.