This chart uses stacked bars to show how total sales are divided among customer segments for each product sub-category. The visualization allows users to hover over legend entries, which highlights the corresponding segment’s bars while dimming the rest. The implementation uses d3.svg.axis, d3.nest, and d3.layout.stack to aggregate and stack the data from the CSV file, with bar rendering using SVG rectangles. A d3-tip tooltip displays detailed values on hover. The color legend, built with d3.legend.color, drives the interactive filtering.