This example visualizes sales distribution by brand as an animated pie chart in SVG. It loads data from a CSV file via `d3.csv`, aggregates sales using `d3.rollup`, and renders slices with the `d3.arc` and `d3.pie` layouts. Hovering over a slice enlarges it via `d3.transition` and displays a bold label with the brand’s total sales. The chart includes a color-coded legend using `d3.scaleOrdinal` and a descriptive title.