Revert "Temporarily revert flat buttons"
Revert "Temporarily revert flat buttons"

This reverts commit 898e51e6ef787fa4c4a8cac28e2d3063c4a2cb03.

andreabondi/paypal-checkout,trainerbill/paypal-checkout,vishakha94/paypal-checkout,paypal/paypal-checkout,bluepnume/paypal-checkout,vishakha94/paypal-checkout,vishakha94/paypal-checkout,trainerbill/paypal-checkout,andreabondi/paypal-checkout,bluepnume/paypal-checkout,mstuart/paypal-checkout,paypal/paypal-checkout,bluepnume/paypal-checkout,mstuart/paypal-checkout,paypal/paypal-checkout,andreabondi/paypal-checkout,mstuart/paypal-checkout,trainerbill/paypal-checkout