why different layouts for same product listing?

Hi,

I have a menu-item, and when you click on it, it will result in the hikashop product listing. I applied a light shadow within the css, added a border and chose a 4 column layout.

Then I chose a 2nd menu item, and also chose the same hikashop product listing option. But the layout of the new menu-item is different from the previous menu-item. How is that possible? I also chose a 4 column layout but I don't understand why the css with the shadow isn't applied to my 2md menu item?

And when I choose for a 3rd menu item, category listing, they layout changes again. Is it possible to copy the layout of the product listing, so that my category listing has got the same layout as the product listing?

Ah, I almost thought that it uses a different css for each newly made menu item...
thanks!