Hello,
You have to know that from our side we design a specific HikaShop structure, unless I'm mistaken this kind of display issue isn't up to us.
Plus, you can understand that this forum's purpose is to help people to use and configure HikaShop, Customization can be a subject too of course, but we only in this case guide people (where to look and how to process) but we can spend time to provide Css code or correct Css customization.
I can only invite you to refer you to Css guides, like
this one
by example.
Sorry for this return.
Regards