Shadow for Quantity on Checkout Page

Hello there,

I was wondering if somebody could assist?

I am looking to create a light shadow over the ‘quantity’ box of the checkout page like the ‘Enter Coupon Code.’

I cannot seem to find the object anywhere in CSS. Is there anybody out there that may be able to help?

Thanks and best wishes,

Benedetto

https://wordpress.org/plugins/wordpress-simple-paypal-shopping-cart/