This bubble chart visualizes the relationship between GDP, population, and life expectancy for 14 countries. Each circle’s x-position maps to GDP, y-position to population, and radius to life expectancy, with country labels and hover highlighting. The SVG chart uses D3 v7 with `scaleLinear`, `d3.csv`, and `axisBottom`/`axisLeft`, reading data from an embedded CSV file. The code styles circles with the `.bubble` class and applies opacity changes on mouseover and mouseout events.