D3 Scatter Plot
A D3 scatter plot displays five Finnish municipalities, plotting their mobile scores against desktop scores on linear scales. Each circle’s fill color derives from a threshold scale, categorizing the average of the two scores into red, orange, or green ranges. The SVG rendering includes axes for both metrics, and hover interactions trigger tooltips showing the municipality name via mouseover, mousemove, and mouseout events. The code uses d3.scaleLinear, d3.scaleThreshold, d3.axisBottom, d3.axisLeft, and d3.select for DOM manipulation.