This scatter plot visualizes a custom shirt dataset, mapping age to the x-axis, height to the y-axis, and weight to the radius of each circle. The circles are colored by shirt size using a hardcoded color scale (e.g., XS is light blue, XXXL is red). The visualization loads a CSV file from a GitHub URL, parses numeric fields, and renders an SVG using D3.js. It uses `d3.csv`, `d3.scaleLinear`, `d3.extent`, and the `axisLeft` and `axisBottom` functions to display the axes with labeled tick marks.