Create a multi-step checkout flow with these screens:

PROGRESS INDICATOR:
- Steps: Cart → Shipping → Payment → Confirmation
- Show current step highlighted
- Completed steps with checkmarks

STEP 1: CART REVIEW
- List of items with:
  * Product image
  * Name and variant
  * Quantity selector
  * Price
  * Remove button
- Subtotal, shipping, tax breakdown
- Total (prominent)
- "Continue to Shipping" button
- "Continue Shopping" link

STEP 2: SHIPPING
- Shipping address form:
  * Full name
  * Address line 1 & 2
  * City, State, ZIP
  * Country dropdown
  * Phone number
- "Save address" checkbox
- Shipping method selection (radio buttons):
  * Standard (5-7 days) - Free
  * Express (2-3 days) - $9.99
  * Overnight - $24.99
- Order summary sidebar (sticky)
- "Continue to Payment" button

STEP 3: PAYMENT
- Payment method tabs: Credit Card, PayPal, Apple Pay
- Credit card form:
  * Card number
  * Expiration date
  * CVV
  * Cardholder name
- Billing address (checkbox: "Same as shipping")
- Order summary sidebar
- "Place Order" button (large, prominent)
- Security badges (SSL, payment icons)

STEP 4: CONFIRMATION
- Success icon/animation
- "Order Confirmed!" message
- Order number
- Email confirmation message
- Order summary
- Estimated delivery date
- "Track Order" button
- "Continue Shopping" button

STYLING:
- Clean, trustworthy design
- Clear visual hierarchy
- Form validation with error messages
- Loading states on buttons
- Mobile responsive
- Secure/professional appearance