frontend.css

I keep making changes here and it says that it was saved successfully but when I reload the pages, none of the changes are really saved.

Where is frontend_default.css stored so I can manually make the changes.

Nevermind...Found it.

media/com_hikashop/css

You should make a copy of the file and call the copy frontend_custom in the same folder and use that CSS file instead of the default one. That way, you won't loose your CSS when updating HikaShop.