This example shows an interactive bar chart of letter frequencies, where clicking a bar highlights it and dims the others, with a title reading "Data Visualization" above the plot. Built with React and D3 v7, it uses `d3.scaleBand` and `d3.scaleLinear` for axes, `d3.axisBottom` and `d3.axisLeft` for gridlines and labels, and a `ResizeObserver` to adapt the SVG to its container. Data loads from a local CSV file via `d3.csv`, and bar styling transitions smoothly on hover and selection.