This line chart visualizes total sales across product categories, using a filled area beneath a steel-blue line to emphasize the trend. Built with D3 v7 and rendered as an SVG, the chart loads CSV data from a GitHub gist and converts sales values from currency strings to numbers. It uses `d3.scaleBand` for the x-axis, `d3.scaleLinear` for the y-axis, and `d3.line` and `d3.area` to generate the paths.