[Feature Request] Adopt Liquid Glass UI on macOS 26+

[SMartorelli]

Is your feature request related to a problem? Please describe.
Apple presented a new unified UI design style called Liquid Glass.

Describe the solution you'd like
Implement the needed changes to adopt this new design and the new "Onboarding" like Apple layout.

https://developer.apple.com/design/human-interface-guidelines/