This example presents a blank interactive canvas that responds immediately to code changes through hot reloading, acting as a live development sandbox for D3.js visualizations. It renders a simple, mutable state represented by draggable nodes and connecting edges, using D3’s force-directed simulation (`d3.forceSimulation`) to animate the layout in real time. The code directly leverages D3’s selection and manipulation API (`d3.select`, `d3.drag`) to handle user interaction, while the underlying data structure is a plain JavaScript array of node and link objects. The entire scene updates seamlessly as the source is edited, demonstrating a minimal but functional prototyping environment.