This responsive scatter plot visualizes the relationship between country population and urban population using world data from 2023. Each circle represents a country, with its color determined by the first letter of the country name via the `d3.scaleOrdinal` color scale. The visualization uses `d3.csv` to load data and `d3.scaleLinear` for axis scaling. Hovering over a data point triggers a tooltip displaying the country name, implemented through `d3.select` and event handlers for mouseover, mousemove, and mouseout.