This example demonstrates how D3 can be used to append and style a circle element, which it renders as a red shape without a visible parent SVG container. The code selects a `div` with the ID `message`, chains `append` operations to create a circle, and applies a red fill using the `attr` method. It loads D3 v5 from UNPKG and relies on the `select` and `attr` APIs, while a separate local module repeats the same circle-creation logic. The visualization highlights basic D3 DOM manipulation and styling through a minimal, single-element output.