platform {
  label: "Platform"

  # `kind` is a semantic tag — what the node *is*. A custom kind imports the
  # @block of the same name as a layout baseline, so both tiers lay out the same
  # way from one rule, with no per-node repetition.
  edge { kind: tier; cdn { label: "CDN" } lb { label: "Load Balancer" } }
  core { kind: tier; app { label: "App" } db { label: "Database" } }

  # The built-in `invisible` kind applies box: none, so this node groups its
  # children for layout only — no border — while keeping its id and path.
  external {
    kind: invisible
    stripe { label: "Stripe" }
    twilio { label: "Twilio" }
  }
}

@layout {
  @block tier { direction: horizontal }

  platform          { direction: vertical }
  platform.external { direction: horizontal }
}