Password Generator User Experience issue

<img width="802" height="405" alt="Image" src="https://github.com/user-attachments/assets/fd29a3c3-cb58-4c09-a309-dbd266f57f27" />

1. The toggle button is used to switch between themes, but it currently lacks a description.
2. There should be an option to set the desired password length before generating it.
3. Add a copy button next to each password container for quick copying.

