A responsive bar chart built with React and D3 v5 updates its axes and bar geometry whenever the container resizes, using a custom `useDimensions` hook with `ResizeObserver`. The chart reads dimensions from the wrapper’s `contentRect`, then redraws with `scaleBand`, `scaleLinear`, `axisBottom`, and `axisRight`, animating bar heights via `transition`. D3’s `join` binds data for mouseenter tooltips and color scales. A draggable resize control adjusts the root width, triggering live updates.