This example visualizes a knowledge graph of learning path components, with 13 nodes grouped into five color-coded categories and 21 directed links showing dependencies. The graph uses a D3 force simulation (`d3.forceSimulation`) with forces for link distance, charge repulsion, x-positioning by group, y-centering, and collision avoidance. Nodes are rendered as SVG circles with labels, while links are drawn as lines with arrowhead markers and empty text paths for potential edge labels. Node positions are also influenced by custom x-center coordinates per group, and dragging is enabled via `d3.drag`.