This interactive stacked bar chart visualizes sales by segment and subcategory, with each bar stacked to represent the total sales per segment. Hovering over a legend item highlights the corresponding subcategory across all segments, while a tooltip shows the exact sales value. The visualization uses D3.js (v3) with the `d3.layout.stack` API for stacking, `d3.legend` for the color legend, and `d3-tip` for tooltips. Data comes from a CSV file, and the chart includes animated transitions when re-sorting the data.