root = Card([header, amountSection, payActions])
header = CardHeader("Invoice #INV-2024-018", "From: Freelance Studio · To: Acme Corp")
amountSection = Card([amountLabel, amountValue, dueInfo], "sunk", "column")
amountLabel = TextContent("Amount due", "small-heavy")
amountValue = TextContent("$2,450.00", "large-heavy")
dueInfo = TextContent("Due by **March 15, 2025**", "default")
payActions = Buttons([payNowBtn, viewDetailsBtn])
payNowBtn = Button("Pay now", null, "primary", null, "large")
viewDetailsBtn = Button("View invoice details", null, "secondary")