{
  "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
  "title": "{{ header }}",
  "width": 400,
  "height": 80,
  "data": {
    "url": "data/penguins.json"
  },
  "mark": "area",
  "transform": [
    {
      "density": "{{ x }}",
      "groupby": ["Species"],
      "extent": [2500, 6500]
    }
  ],
  "encoding": {
    "x": {"field": "value", "type": "quantitative", "title": "{{ title_x }}"},
    "y": {"field": "density", "type": "quantitative", "stack": "zero"},
    "color": {"field": "{{ field_x }}", "type": "nominal"}
  }
}