This example visualizes the relationship between fuel efficiency (mpg) and horsepower for classic automobiles, with points colored by country of origin and tooltips revealing model names. It uses the Vega-Lite API (`vl.markCircle`, `vl.x().fieldQ()`, `vl.color().fieldN()`) to declaratively encode the data, with rendering handled by Vega and Vega-Lite. The CSV dataset is fetched via d3’s `csv` function, and the visualization adapts to the browser window using `.width()` and `.height()` with autofit behavior.