[BUG Fixes]
[olist]
[*] Fixed being not able to unlock some difficulties in certain cases
[*] Fixed deduction failure when unlocking AB branch.
[/olist]
[Experience Optimization]
[olist]
[*] Optimized the UI design of unlocking difficulties.
[*] Added a new feature that keyboard shortcuts now can be viewed when pressing Tab key.
[/olist]