some hikashop css classes set

need some css classes set
I use a template from yootheme (micasa)
but the css off off the micasa theme overrules
I use the Style pictureblue

But if you see my pages its not looking like Style pictureblue
www.sanitair-installatie.be/index.php/co...as-chroom?Itemid=200

Ask yootheme for any help they say;

The theme does not have any CSS for Hikashop. If Hikashop has uniques CSS classes, you will not have a problem like this.
You can load you own CSS , see Add new CSS, JS or Fonts and How to Customize

So if you can set the classes you can help me

regards