products grid

-- url of the page with the problem -- : http//barbaragiganti.com
-- HikaShop version -- : 2.6.3
-- Joomla version -- : 3.7
-- PHP version -- : 5.6.30

Hello

I'm trying to make a product listing in a grid which I would like without margins nor padding,
so to have only product images clickable.

So far, I created a product listing module, and loaded it into a Quix page.


Trying to figure out how to change the CSS is not working.
Can you please give me a hint?

thanks