Hello,
1) I see related products on your site http://prntscr.com/r1vrpb
Related Products is a section on some templates that pulls products from your store that share the same tags or categories as the current product.
https://docs.woocommerce.com/document/related-products-up-sells-and-cross-sells/
WooCommerce does not have any otions to choose what products to show as the related. You can choose only upsells by yourself.
2) CSS code works only with styles, it does not make any option to appear, PHP and JS work with options.
Regards