This reusable line chart visualizes average monthly temperatures in Dallas from 2015 to 2023, with each year’s temperature trend shown as a smooth, monotone curve. The chart uses D3 v7’s `d3.line()` with `curveMonotoneX` to generate the SVG path, along with `scaleLinear` for both axes. Gridlines are added via custom axis ticks, and the y-axis uses a fixed domain of 500 million to 1.5 billion, reflecting the dataset’s population values. The code reads from a CSV file and renders the visualization as an SVG element with a white background and shadow styling.