This example presents two SVG visualizations of salary data. The first is a horizontal bar chart showing average salary by experience level, computed with `d3.group` and `d3.mean`. The second combines a blue line for average annual salary with a red line for COVID-19 new cases per year, using `d3.rollups` and `d3.line` on a dual-axis chart. Both are rendered with D3 v6, loading data from CSV files, and styled with basic CSS.