This interactive scatter plot visualizes the relationship between pet age and adoption fee, with point size encoding weight. Using D3 v7 with an SVG rendering, the `scatterPlot()` function configures linear scales for both axes via `d3.scaleLinear` and a square-root scale for bubble radius. It employs `d3.scaleOrdinal` with `d3.schemeSet2` to color-code points by pet type. The chart reads a CSV from a GitHub gist, and a CSS-styled tooltip appears on mouse movement via `.on('mousemove')`, displaying pet details. Grid lines and axis labels enhance readability.