We've launched an improved shopping cart design that looks great both on desktop computers and mobile smartphones.  There's nothing you need to do to enable this new design.  This new design will provide a much better checkout experience for your customers if they are on mobile devices and a better designed experience on desktop.

Here's what it looks like:

New cart design on desktop:

New cart design on mobile:

New Checkout screen on desktop:

New checkout screen on mobile (with order details collapsed):

New checkout screen on mobile (with order details expanded):

New pay with PayPal screen desktop:

New Pay with Paypal Screen Mobile:

We are still working on some further improvements which include paying with a credit card (via Stripe) and the ability to preview the cart via a slide out tab on your website.  Those projects are still in development and testing.