This example visualizes the relationship between fuel efficiency (mpg) and horsepower for cars, with each point colored by country of origin and sized by vehicle weight. It uses data from the UCI Machine Learning Repository’s Auto MPG dataset, loaded via `d3.csv`. The graphic is built declaratively using the Vega-Lite API, specifying a circle mark with encodings for position, color, and size. The code registers Vega, Vega-Lite, and the Vega-Lite API, then renders an interactive SVG chart fitted to the browser window, with a tooltip provided by Vega-Tooltip.