This example shows the distribution of two variables as overlapping histograms, with semi-transparent bars in teal and dark purple to reveal how their ranges compare. The visualization is built with D3.js v4 and rendered as SVG, using `d3.histogram()` to bin the data and `d3.scaleLinear()` for the axes. The code loads a CSV file, filters it by a `type` column, and draws both series on a shared x-axis while scaling the y-axis to the maximum bin count. A handmade legend identifies the two variables.