Fix scrollbars on windows and make them look the same as on linux/macos.

[RedddFoxxyy]

Issue: Inconsistent Scrollbar Appearance Across Linux and Windows

The scrollbars in our application look different on Linux and Windows, which affects the UI's consistency.

Scrollbar Appearance on Windows:

Linux Scrollbar

Scrollbar Appearance on Linux:

Windows Scrollbar

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Suggested Solution:

This inconsistency can be resolved by customizing the scrollbar styles in app.css.