Title Bar Height Impact on Window Size in SwiftUI on macOS

In a SwiftUI macOS application, when removing the title bar by setting window.titleVisibility to .hidden and window.titlebarAppearsTransparent to true, the title bar space is still accounted for in the window height. This results in a delta (red area) in the height of the window that cannot be ignored by usual SwiftUI view modifiers like .edgesIgnoringSafeArea(.top). My actual view is the blue area.

I want to have the view starting in the top safeArea and the window to be the exact size of my view. I am struggling to achieve this. I have also tried with window.styleMask.insert(.fullSizeContentView) to no effect.

Can I get some help? 🙂

Here is my source code to reproduce this behavior:

windowApp.swift

@main
struct windowApp: App {
    @NSApplicationDelegateAdaptor private var appDelegate: AppDelegate
    
    var body: some Scene {
        WindowGroup {
            ContentView()
                .edgesIgnoringSafeArea(.top)
                .background(.red)
                .border(.red)
        }
    }
}

class AppDelegate: NSObject, NSApplicationDelegate {
    func applicationDidFinishLaunching(_ notification: Notification) {
        if let window = NSApplication.shared.windows.first {
            window.titleVisibility = .hidden
            window.titlebarAppearsTransparent = true
            window.styleMask.insert(.fullSizeContentView)
        }
    }
}

ContentView.swift

import SwiftUI

struct ContentView: View {
    var body: some View {
        VStack {
            Image(systemName: "globe")
                .imageScale(.large)
                .foregroundStyle(.tint)
            Text("Hello, world!")
        }
        .frame(minWidth: 400, minHeight: 200)
        .background(.blue)
    }
}