Payment Selector

How the shopper pays: one ruled list of methods (card, wallet, pay in instalments, bank) where the chosen one opens onto your payment provider's own fields. It never renders a card-number field: each panel is a renderPanel slot for Stripe's Payment Element, Adyen's Drop-in, PayPal or a redirect notice, kept mounted once opened so a provider iframe keeps the half-typed card. Panels sit outside the radio group, so arrow keys move between methods without reaching into a provider's fields, yet render under their own method as one object. Instalment lines from the order total, unavailable methods with their reason in words, a provider error in the open panel, loading and empty states. The heavy rule slides to the chosen method and its panel grows to its measured height (Motion; a fade under reduced motion).