使用Paypal在上下文中使用Paypal Express Checkout的一个小问题

I'm using the library PayPal-PHP-SDK and the In-Context. When I click on the checkout button, a pop-up appears (like it should) but instead of responsive payment, it's just like the normal payment page and I have to scroll right to enter my credentials. Is there a way I can make the payment page in the pop-up responsive so it will be much more comfort?

Update 1

I'm testing it from my localhost. screenshot:

In-Context PayPal

sounds like a layout issue of some sort as that's not what I experience here. Can you maybe submit a link to your site so I can look at it?