.shopify-payment-button__button {
  background: #232323;
  border-color: #232323;
}

@media (min-width: 1025px) {
  .productView-payment
    .shopify-payment-button
    .shopify-payment-button__button:hover {
    border-color: #232323 !important;
    border: solid 1px;
  }
}