D3 Multi Line Chart
This interactive D3 multi-line chart compares U.S. foreign assistance dollars across five global regions, with a radio-button toggle switching between economic and military aid datasets. The visualization plots yearly spending trends using colored lines, with axes formatted in millions and a hover tooltip for details. Built with React and SVG, it uses d3.csv to load remote data, d3.scaleOrdinal for region colors, d3.line with curveBasis for smooth paths, and transition.attrTween-style animation (via transition().duration()) when toggling datasets, updating the line geometry accordingly.