This example renders a line chart of San Francisco weekly temperatures using the Vega-Lite API within a D3.js framework. The visualization displays temperature trends over time, with tooltips showing exact temperature values on hover. The code uses `vl.markArea` with encoded x- and y-fields, pulling data from a CSV via D3's `csv` loader. It integrates Vega, Vega-Lite, and the Vega-Lite API for declarative visualization, while customizing axis and label styling through a separate config file.