Add search box margin for compact taskbar size

[Ervoconite]

Preflight Checklist

• I have searched all open and closed issues for the same feature request without success.

Problem Description

环境是win11+startallback+bar，但是他应当有个边距的设置，更符合原生且好看。
The environment is win11+startallback+bar, but it should have a margin setting, which is more native and beautiful.

Proposed Solution

像这样。
Like this.

Alternatives Considered

none

Additional Information

No response

[Ervoconite]

还有，需要一个透明度的设置。
Also, a transparency setting is required.