Software: Youtube (Web Usage)
User query: Change the theme of Youtube from Device Theme to Dark Theme
Difficulty: simple
Ground-truth plan:
Task 1: Change YouTube Theme to Dark Theme
Subtask 1: Click on the 'Account menu' or 'Avatar image' in the top right-hand corner of the YouTube page.
Subtask 2: Click on 'Appearance: Device theme' in the dropdown menu.
Subtask 3: Click on 'Dark theme' to select it.