This example demonstrates population growth in India from 1960 to 2020 with a blue area chart and a three-pixel-wide line overlay. Built with React and D3 v7, the chart uses `d3.scaleLinear` for both axes and `d3.area` to generate the filled path. SVG rendering is used, with axes created via `d3.axisBottom` and `d3.axisLeft`, and standard D3 selectors append the visualization to the root element. The data is a small inline array of year-population pairs.