Design a user interface for managing invoices and their line items. Include fields for invoice details such as invoice number, dates, status, payment status, amounts, customer details, and order information. Also, incorporate a section for adding/editing line items with fields like item description, unit price, quantity, and calculated line totals. Ensure the UI is intuitive, supports data validation, and provides a straightforward way to save invoice information. | A shadcn/ui and v0 generation - v0
