areaY the rows and the x and y fields to fill the space under one series, smoothed with a natural curve.curve to curveLinear to join the points with straight lines.curve to curveStep for a value that holds until the next point, like a price or a plan.z and color to a series field and layout to stack() to pile the series on top of each other.stack({ offset: "normalize" }) to stack the series as shares of each month's total.gradients and point fill at them with url(#id) to fade each series toward the baseline.y scale a domain and tick values to show a value axis with chosen gridlines.Badge dots under the chart, colored from chartColors.series, to name each series.Select changes, to show the last 7, 30 or 90 days of daily data.RendererChart with a motion() renderer so the area springs between ranges, with a dot and crosshair on the focused day.