This interactive scatter plot visualizes the relationship between vehicle weight, horsepower, and fuel efficiency (mpg) using the classic auto-mpg dataset, loaded via `d3.csv` from a remote GitHub Gist. Encoded as circles with size and color mapped to quantitative fields, the chart reveals correlations among these performance metrics. Built with the Vega-Lite API for programmatic specification, it renders through Vega, Vega-Lite, and the `vega-tooltip` Handler, with automatic resizing to fit the window.