Smaller product title and price font size on checkout page

Hi team,

Would you please help me change the products title and price font size to be 14px on the checkout page for all devices?
1. We use CheckoutWC plugin, the custom css option route is here, CheckoutWC->Appearance-> Design-> CSS customize template CSS.
2. On mobile device, can you also reduce the logo size little bit and reduce the spacing up and down as marked in the attached picture, the previous developper only optimized the logo size for desktop not did on mobiles.

Appreciate!