Landing Page Pattern: E-commerce Checkout & Cart. Keywords: checkout, cart, e-commerce checkout, two column, order summary, payment form, buy, purchase, shopping cart, upsell, cross-sell, bag, basket, multi-step, progress bar, shipping, fees, transparent pricing, fee breakdown, marketplace checkout, service fee. Section Order: 1. Two column (60/40): Left shipping/billing form + Right order summary with items and totals, 2. Express checkout buttons (Apple Pay / Google Pay / PayPal), 3. Cart items with quantity controls + cross-sell recommendations, 4. Itemized fee breakdown (subtotal + service fee + taxes + total), 5. Optional progress bar for multi-step flows, 6. Place order CTA. Primary CTA Placement: Place order button bottom-right + Express checkout top + Optional progress bar per step. Color Strategy: Left: White form bg. Right: Light grey #F5F5F7 summary panel. CTA: Brand primary. Express: Native button colors. Progress bar: Active in brand color, completed green #16A34A, pending grey #D1D5DB. Fee lines: Dark #1A1A1A. Savings: Green #16A34A. Sale/discount: Red #DC2626.. Recommended Effects: Input focus highlight, order summary sticky on scroll, express checkout shimmer, form validation inline, progress bar fill animation, quantity animation, upsell carousel slide, fee line item reveal. Conversion Optimization: Two column standard (60/40 split). Show shipping cost early. Trust badges near payment. Express checkout reduces friction 30%. Upsell/cross-sell in summary increases AOV 10-30%. Show free shipping threshold. Show all fees before final CTA (no surprise costs). For multi-step: reduce fields per step, allow back navigation. Marketplace: host guarantee + cancellation policy visible..