Quantity Box Not Showing Number

My HikaShop Essential does not show the number within the Quantity boxes. I have the Quantity box next to the "Add to Cart" button, and after entering a number it doesn't show. Upon checkout, the same problem occurs; the quantity is not showing. So if I enter a "2" into the checkout quantity box and refresh, it will calculate a quantity of "12" as if it just added a "2" to the original "1". The user cannot see the actual quantities being entered, and this makes the product unusable. Any pointers appreciated.

Thanks! Where do I find the "frontend_custom.css" file?

Update: Ah! Found it within the Configurations of HikaShop. Thank you!!