---
root:
  items:
    - type: rect
      bounds: [25, 25, 100, 100]
      color: red
    - type: stacking-context
      bounds: [0, 0, 200, 200]
      filters:
        - "opacity(0.5)"
      items:
      - type: rect
        bounds: [0, 0, 100, 100]
        color: blue
      - type: rect
        bounds: [50, 50, 100, 100]
        color: green