For each ridge in the layer's order, the place of its
<Area> among the chart's, from 0
OptionalchartId: stringWhen set, scopes the selectors to the chart's article
OptionalpanelScope: stringWhen set, additionally scopes them to one panel
One selector per ridge
One selector per ridge of a ridgeline, each naming the filled band of the
<Area>at that place among the chart's<Area>s.The one class selector a ridgeline uses resolves the bands in the order the
<Area>s are declared, which is the order the groups first appear indata. A layer that lists its ridges in another order -- bottom first, asRidgelineTracereads them -- would pair each with another ridge's band, so each is named by its own<Area>'s place, counted among the areas alone, as seriesDotSelectors counts the dots' groups.