This example shows a bar chart of letter frequencies from a small CSV dataset, styled with a minimalist aesthetic and interactive click-to-highlight behavior. It uses React with a custom `useDimensions` hook and a `ResizeObserver` to track container size, while D3 v7 handles SVG rendering, scales, and axes. The chart’s bars transition their fill and opacity on hover and selection, and the D3 `scaleBand` and `scaleLinear` APIs map the data. The code splits into modular render functions like `renderBars` and `renderBarElements` for maintainability.