This example demonstrates a component-based template for building D3 visualizations. It establishes a structured SVG canvas with configurable spacing for header, axis, and label regions, using CSS variables for theming via the `branding` and `spacing` modules. The `canvasPlot` function generates a background and optional gridlines, while the main title and subtitle are set through a getter-setter pattern. The code relies on D3 v7 selections and joins, with a `plot` module prepared as a scaffold for future chart types.