This visualization shows the UK energy flow Sankey diagram with animated particles traveling along each link to illustrate transfer dynamics. The code uses D3.js v3 with the custom `d3.sankey.js` layout, combining SVG for nodes and links with a Canvas overlay for particle rendering. Particles are generated based on link frequency, move along the SVG path geometry using `getPointAtLength`, and are drawn with the Canvas 2D API. The example demonstrates DOM manipulation through D3 drag behavior for interactive node repositioning.