This scatterplot explores the relationship between engine size and fuel efficiency for various vehicle types, with each point’s radius encoding horsepower and its color representing the vehicle’s category. The visualization is built using D3 v6’s `select`, `scaleLinear`, `scaleOrdinal`, `csv`, and `axisBottom`/`axisLeft` APIs, rendering as an SVG in the browser. Data is loaded from a remote CSV hosted on GitHub, with all numeric fields parsed before being plotted.