[Feature Request] Buttons enhancement

[Molwi]

Is your feature request related to a problem? Please describe.
Not really a problem, I just wanted to make my bar look better

Describe the solution you'd like
Add Box Shadow not only for the bar, but the buttons themselves.
And make so you could merge those buttons together, like in different Waybar configurations

Describe alternatives you've considered
Maybe just add full CSS editing

Additional context
Add any other context or screenshots about the feature request here.

If these features already exist, please tell me where can I locate them