This bar chart shows total sales by product category, using data loaded from a CSV file. The visualization is built with D3 v6 and rendered as SVG, applying linear scaling to sales values and band scaling to categories. It uses `d3.csv`, `scaleLinear`, `scaleBand`, `axisLeft`, and `axisBottom` to construct the chart, with each rectangle’s height and width determined by the data values. The data is preprocessed by converting sales strings to numbers.