This stacked bar chart shows yearly sales totals for grocery, appliance, and toy categories across 2018–2020. Each bar segment represents one product category, with a legend identifying colors and a hover tooltip displaying the exact sales value. The visualization uses D3 v7’s `d3.stack`, `d3.scaleBand`, and `d3.scaleLinear` to generate SVG elements from the provided CSV data. Interactive features rely on D3’s `.on('mouseover')` and `.on('mouseout')` event handlers, while axis labels and tooltips are styled using inline CSS.