This example visualizes the relationship between vehicle horsepower, weight, and fuel efficiency across different origins using a scatter plot. The visualization is built with the Vega-Lite API, which programmatically constructs a Vega-Lite specification through chained method calls such as `vl.markCircle()` and `vl.encode()`. Data comes from an auto-mpg CSV loaded via `d3.csv`, and the chart renders as an SVG using Vega’s rendering engine with tooltip support from Vega-Tooltip. The visualization is configured with custom axis and label styling to improve readability.