This example displays a smoothed density estimate of the relationship between engine displacement and horsepower, with tooltips revealing car model names. Built with the vega-lite-api library, the visualization loads auto-mpg data from a CSV via d3.csv. The chart uses a filled, semi-transparent line mark to approximate a density plot, configured with custom axis and label styling. Vega-Lite handles rendering, while Vega-Tooltip provides interactive hover details.