This combined bar and line chart visualizes monthly sales and profit for Product A from 2018 to 2022, with semi-transparent green bars representing sales (right axis) and a red line with dots representing profit (left axis). Interactive hover effects increase bar opacity and dot radius, while grid lines and axis labels clarify the dual-scale comparison. The example loads CSV data from GitHub using d3.csv, filters it for Product A, and builds the SVG scene with d3.scaleTime, d3.scaleLinear, d3.axisLeft, d3.axisRight, and d3.axisBottom, all within the D3 v7 framework.