Support customizing Padding and Margin.

[FledgeXu]

Is your feature request related to a problem? Please describe. I wanna hide the window bar but still keep the top padding like in this picture.

Describe the solution you'd like Support Settings like:

Set PaddingTop 20
Set PaddingBottom 20
Set PaddingLeft 20
Set PaddingRight 20
Set MarginTop 20
Set MarginBottom 20
Set MarginLeft 20
Set MarginRight 20

Describe alternatives you've considered Idk, maybe hide window bar?