Fork of Line Chart multiple lines | interractive Legend
This visualization displays a week of temperature readings for multiple cities, rendered as colored lines. The interactive legend allows users to click on a city name or the line itself to isolate that city’s data, while non-selected lines fade to 20% opacity. Built with D3 v5, the chart uses SVG for rendering, `nest()` to group data by city, `scaleTime()` and `scaleLinear()` for axes, and the provided `colorLegend` function to manage selection states via click handlers.