This bar chart visualizes average horsepower for different car brands, sourced from a car models dataset hosted on GitHub. Built with D3 v7 and rendered as SVG, it uses `d3.csv` to load data, `d3.rollup` with `d3.mean` to aggregate, and `d3.scaleBand`/`d3.scaleLinear` to map brands and values. Hovering highlights bars in orange, and axis labels are rotated for readability.