This bubble chart visualizes the correlation between GDP per capita and happiness scores for 20 countries, with bubble radius scaled to population size. Built with D3.js v7 and rendered as SVG, it plots points using linear scales for both axes. The chart includes an interactive tooltip that appears on hover, showing detailed data for each country, and features a legend indicating population size ranges. The data is loaded from a CSV file and processed using D3's `d3.csv` method.