This example demonstrates an interactive force-directed graph built with React and D3 v6. A hierarchical dataset is flattened into nodes and links, then rendered as circles and lines using SVG. The simulation uses `d3.forceSimulation` with center, charge, collide, and link forces. Moving the mouse dynamically adds `forceX` and `forceY` forces that pull nodes toward the pointer, with strength varying by node depth. Clicking applies a `forceRadial` orbit force around the clicked point and draws a green circle to indicate the orbit radius.