Project: mobx
Task (challenging): Add new page '/rooms':
1) Add a button with the text '🚪' in Header, when clicked, jump to new page '/rooms'
2) Add a "Create Room" button with className '.create-room-btn' that opens a room creation form.
3) The room creation form should include a labeled input field for room name ("Room Name") and a "Create" button to submit the form and create a new game room with a unique ID. Don't enter the room instantly.
4) Each room should be displayed as a card with className '.room-card' showing room name, creator's username, and current status.
5) Sync room status between all open tabs/windows.
Constraint: DO NOT use any third-party packages; ONLY React/MobX APIs are permitted; Use MobX to manage the state and sync logic.