scroll to zoom — the cluster under the centre opens, the rest stay discs · hover a cluster to see its edges · drag to pan · shift+drag selects a region · click a cluster to pin it open · double-click to fly to it · Esc clears
The HUD needs d3 from cdnjs.cloudflare.com and a data block (window.__CG_MODEL or window.__CG_ROWS); one of them is missing here.