This scatterplot displays GDP variation over time for the USA and Germany, with points colored by country from a CSV file. Users can click a color legend to filter the visualization, dimming points from unselected countries. Built with D3 v5, it uses `scaleLinear` for axes, `scaleOrdinal` with `schemeSet2` for colors, and custom modules `scatterplot` and `colorLegend` to render SVG circles and interactive legend elements.