Coupon Code Field Shopp Template

I need a little help. Im using the Shopp plugin but am having trouble with my coupon code.

Here is the code I want to implement so users can put in a code
<?php shopp(‘cart.apply-code’,’class=discount-input&value=Apply Discount Code’); ?>

Unfortunately I cant figure out why im having trouble getting it to match my sites style. Ive tried a number of things but nothing seems to be working.

It just shows up as text without an outlined text box. And what I want is for it to be a bordered box for the code and a button to click…

Here is my sites cart https://www.hnybaby.com/shop/cart/

Thanks in advance