This example visualizes the relationship between vehicle weight, horsepower, and fuel efficiency using a scatter plot, with each car represented as a circle colored by weight and sized by miles per gallon. The visualization is built with the Vega-Lite API, which registers Vega and Vega-Lite libraries to create the chart programmatically. Data is loaded from a CSV file via d3.csv, and the final SVG output is rendered to fill the browser window. Axis styling and tooltips are customized through the provided Vega-Lite config and the vega-tooltip handler.