This example pairs a heatmap with Vega-Lite’s declarative API to visualize daily temperature readings. The chart plots date fields on both axes, using semi-transparent pink points to reveal density patterns, with tooltips showing the raw Temperature value. The visualization is built with `vega-lite-api`, registered alongside `vega` and `vega-lite`, and loads CSV data via d3’s `csv` function. Custom config adjusts axis labels and tick colors for readability, while the canvas is sized to fit the full viewport.