root = Card([header, amountCard, dueDate, payActions])
header = CardHeader("Invoice #INV-2024-081", "Freelance Web Development Services")
amountCard = Card([amountLabel, amountValue, currencyValue], "sunk", "column", "xs")
amountLabel = TextContent("Amount Due", "small")
amountValue = TextContent("$4,850.00", "large-heavy")
currencyValue = TextContent("USD", "small")
dueDate = TextContent("Due **October 15, 2024**", "default")
payActions = Buttons([payNowBtn, viewDetailsBtn])
payNowBtn = Button("Pay Now", null, "primary", "normal", "large")
viewDetailsBtn = Button("View Invoice Details", null, "secondary")