Extra keys not allowed

I have hard time to understand the HA error messages. Now I puzzling over a simple topic. From here I pasted the “dark condition” to my automations:

condition:
    condition: or
    conditions:
      - condition: sun
        after: sunset
        offset: "02:00:00"
      - condition: sun
        before: sunrise
        offset: "-02:00:00"

in the following context:

- id: radar_est_triggered
  alias: Radar est
  hide_entity: false
  initial_state: true
  trigger:
    platform: state
    entity_id: binary_sensor.radar_est
    to: 'on'
  condition:
    condition: or
    conditions:
      - condition: sun
        after: sunset
        offset: "02:00:00"
      - condition: sun
        before: sunrise
        offset: "-02:00:00"
  action:
  - data:
      message: Radar est!
    service: notify.pushbullet

but HA gives me this error:

Failed config
automation:
- Invalid config for [automation]: extra keys not allowed @ data[‘condition’][0][‘conditions’][0][‘after’]. Got None
extra keys not allowed @ data[‘condition’][0][‘conditions’][0][‘offset’]. Got None
not a valid value for dictionary value @ data[‘condition’][0][‘conditions’][0][‘condition’]. Got None
required key not provided @ data[‘condition’][0][‘conditions’][0][‘entity_id’]. Got None.

It says that “extra keys are not allowed” and then “got none”. So, there is such an “extra key” or not? And what’s that?

In the condition section it must read after_offset and before_offset, not just offset

You’re right - my fault.
But the error message is quite misleading! Why it isn’t just something like: " ‘after’ property not recognized"?

extra keys not allowed @ data[‘condition’][0][‘conditions’][0][‘after’]. Got None

seems confusing, even in plain English!