 card number, expiry, CVC fields
                    PayPal: PayPal login or authorization button
                    Other gateways: Provider-specific fields Stripe: Credit card number, expiry, CVC fields PayPal: PayPal login or authorization button Other gateways: Provider-specific fields Required: Customer must select payment method before paying Pay Now Button: Submits order and processes payment (disabled until gateway selected) Return to Cart Link: Navigate back to shopping cart page without completing purchase Portal Integration: Pre-fills customer information if Portal client logged in Country/State Cascading: State dropdown updates automatically when country changes Order Receipt Viewing: Supports viewing completed order via action=view_receipt parameter Pending Order Checkout: