Checkout requires four or fewer logical steps

Every additional checkout step sheds buyers. Baymard's large-sample checkout research shows conversion rate falls measurably with each extra page between cart and confirmation. Forcing shoppers through Address, Shipping, Billing, Coupon, Payment, Review, and Confirm as seven distinct pages is a self-inflicted revenue cut. Long flows also amplify error-recovery pain — a validation failure on step six means re-traversing the whole sequence — and mobile users drop off at the highest rates on multi-page flows.

Collapse related concerns into single pages in src/app/checkout/. Combine shipping address and shipping method on one page, keep payment and review on a second, and use the confirmation as step three. For small catalogs, render the full flow in src/app/checkout/page.tsx as a single page with section-based validation.

{step === 'shipping' && <ShippingForm />}
{step === 'payment' && <PaymentForm />}
{step === 'review' && <ReviewOrder />}