This bubble chart displays the correlation between GDP per Capita and Happiness Score across 20 countries, with bubble size encoding population. Built with D3.js v7, it uses `d3.scaleLinear` for the x and y axes, and for the bubble radius scale. The visualization is rendered as SVG with a custom tooltip that appears on mouseover, showing country-specific details. Data is loaded from a CSV file using `d3.csv`, and includes a legend in the upper right indicating population size ranges.