This visualization displays unemployment rates across US states for the year 2022, rendered as a single-column heatmap using shades of blue. Built with D3 v6, it uses `d3.scaleBand` for the x and y axes, `d3.scaleSequential` with an interpolateBlues color scale, and SVG rectangles for each state cell. Interactive tooltips appear on mouseover using D3's selection API, showing state name, year, and unemployment percentage. Data comes from a CSV file on unemployment per US state.