How to Create a Shadow in SwiftUI Only at bottom

I'm trying to create a shadow effect in SwiftUI that only appears beneath the lower half of a rectangle. Current Code:

struct ContentView: View {
    var body: some View {
        Rectangle() 
            .fill(Color.blue) // Fill the rectangle with blue color
            .frame(width: 200, height: 100) // Set the rectangle's dimensions
            .shadow(radius: 10) // This applies shadow to the entire rectangle
    }
}

Problem: In the code above, the shadow is applied to the entire rectangle. However, I only want the shadow to show beneath the lower half of the rectangle.

You need to add the shadow as an overlay so it can be offset and then mask it.

struct BottomShadow: View {
    var body: some View {
        Rectangle()
            .fill(Color.blue)
            .frame(width: 200, height: 100)
            .overlay(alignment: .bottom) {
                Color.blue
                    .shadow(radius: 5, y: 5)
                    .mask{
                        Color.black
                            .offset(y: 15)
                    }
            }
   
        Spacer()
    }
}

#Preview {
    BottomShadow()
}

Resulting in this:

If you play with the size of the overlay, the values and order of the modifiers, you can also get creative:

Rectangle()
            .fill(Color.blue)
            .frame(width: 200, height: 100)
            .overlay(alignment: .bottom) {
                Color.blue
                    .frame(height: 5)
                    .mask{
                        Color.black
                            // .offset(y: 5)
                            // .padding(.top, 3) // <- modifiers here can be used for additional control
                    }
                    .shadow(radius: 3, y: 10)
            }

This will give a shadow that can be somewhat in the air, but also slightly extends to the sides, rather than be clipped like the previous one.