incorrect display on smartphones

-- url of the page with the problem -- : www.rtmetalli.it
-- HikaShop version -- : 2.6.4
-- Joomla version -- : 3.5.1

hi, I set three columns for displaying products list, on descktop the result is ok. When you step to the display on smartphones articles moving in this 2-1-2-1-2-1 sequence and so on. I wish the display was 2-2-2-2-2. I set this class in the css:

@media only screen and (max-width: 970px) {
.hikashop_subcategories div.hikashop_category, .hikashop_products_listing div.hikashop_product
{width: 50% !important;}
}
@media only screen and (max-width: 750px) {
.hikashop_subcategories div.hikashop_category, .hikashop_products_listing div.hikashop_product
{width: 100% !important;}
}

how do I fix?

You are a great nicolas, the change was to my liking, Thanks
Now how do I get pagination bottom of the page?
Thank you again for you patience.

Nicolas thanks, your help was very valuable. I only had to change your class
.hikashop_products_pagination_bottom{ clear:both !important; }
with
.hikashop_products_pagination div{ clear: both !important; }

I still want to ask you something, what class I have to change if I just want to change the button add to shopping list products, leaving unchanged that of the product? I am attaching reference images

Hello,

Can you tell us what you exactly want to achieve through some screenshots for example so that we can understand your issue ?

Thank you.

I would change the button style add to shopping list products in a carriage shaped button. The button add to cart in product page must remain the same.
Sorry for my bad English and

Dear Sir,
I added css code in frond end cssfile of frontend_customer1.css:

Thanks Nicolas, Very good! It is OK now.