This dashboard presents two linked views of 2025 sales data for three products. A multi-series line chart, built with `d3.scaleTime`, `d3.scaleLinear`, and `d3.line`, tracks the sales of Products A, B, and C, with a monotone curve. A second combo chart combines gray bars for advertising spend, scaled on the left axis, with a black line for profit margin, scaled on the right. Both visuals use SVG rendering via the d3 v7 library, loading data from a CSV file.