Prestashop highlight promo product

I need to higlighlight the cart line containing a gift product
(a product given by the standard promo code, when we set it to offer a product, for certain conditions).

You need to add a class or id on the detail line template WHEN and only when a product has been added because of a promo rule.

Please do not apply if you don't know the solution, i need a prestashop expert.
Also we will need to ovveride and not modify base template)

Thanks !