Shop Module - Categories list with float: left

Hello
I cannot find where to change the css of the list of categories in the shop module.

When I check with firebug I can see that the problem why the list is not one line per cateogory is:
.hikashop_category_list_item, .hikashop_product_list_item {
float:left;
}

I need to check the float: left in order to make sure that each category is on one line. Because now the category on the third line is followed by the category 4 with no space. That is ugly.

Any ideas?

thank you

Thank you very much. I changed it to clear:both and it worked.
Have a nice day and thank you again for the very fast answer.