This example visualizes the relationship between fuel efficiency and engine power for various car models, using a scatter plot where point color indicates country of origin and point size reflects vehicle weight. The visualization is built with Vega-Lite’s API, with the specification defined in `viz.js` and rendered via D3. Data comes from the UCI Auto MPG dataset, loaded asynchronously using `d3.csv`. The chart is configured with custom axis styling from `config.js`, and includes interactive tooltips via `vega-tooltip`.