This interactive bar chart displays letter counts loaded from a CSV file, with bars that respond to clicks by highlighting the selected letter and dimming others. Built with React and D3 v7, the visualization uses `scaleBand` and `scaleLinear` for positioning, while a `ResizeObserver` in `useDimensions` tracks container size changes. The chart renders as SVG with labeled axes, gridlines, and a title, all styled through CSS transitions that animate bar fill and opacity changes on selection.