A directed-flow diagram maps notification counts from a total source through matched and scrap categories into downstream targets. The visualization uses a custom `d3.sankey` layout with SVG rendering, featuring draggable nodes and hoverable links with adjustable stroke opacity. Node heights encode link values, and the layout algorithm iteratively optimizes node positions to reduce collisions. Data comes from a static JSON file, with node labels styled in bold Verdana text and the chart embedded in a React application shell.