This interactive bar chart demonstrates the transition between grouped and stacked layouts using synthetic, smoothly-varying data. The visualization uses D3 v6’s scalable vector graphics (SVG) rendering with animation to morph bar positions and heights. Users toggle layout modes and toggle individual series on or off via custom radio-style buttons, which are built with D3 selections and manual layout positioning. The chart relies on `d3.stack` for stacked series data, `d3.scaleBand` for the x-axis, and CSS transitions for smooth updates.