This example presents an interactive pie chart built with D3.js v7 that visualizes static sales data across four product categories. The chart renders as an SVG, with each category represented by a colored slice, and uses a hover interaction to display a tooltip showing the category name and its sales value. The code employs `d3.pie()` to compute the arc angles, `d3.arc()` to generate the slice paths, and `d3.scaleOrdinal` with `d3.schemeCategory10` for coloring. A separate HTML legend lists each category with its corresponding color swatch.