{"version":"1.0","type":"rich","title":"Selecting a Year on a Line Chart","description":"Multiple colored lines trace regional population changes from 1950 to 2100, using data from the UN Population Estimates and Medium Variant datasets. A vertical black line marks the currently selected year, which updates when the user hovers over the chart via a mouse-interceptor rectangle that calls `setSelectedYear` with `xScale.invert`. The chart uses d3.scaleTime, d3.scaleLinear, d3.line with curveBasis, and d3.axisLeft/axisBottom; a separate color legend built with `colorLegend.js` identifies each region.","provider_name":"VizHub AI Studio","provider_url":"https://vizhub.com","html":"<iframe src=\"https://vizhub.com/viz/839cc38d1d4948368d8a33f3e3c7b31e?mode=embed\" width=\"960\" height=\"500\" scrolling=\"no\" frameborder=\"0\"></iframe>","width":960,"height":500,"cache_age":3600}