Overlapping card shadows in SwiftUI

OverlappingCardShadows.swift

// Inspired by LearnSketch.com's video: https://youtu.be/xVREimb1Nnw

import SwiftUI

struct ContentView: View {
    var body: some View {
        ZStack {
            Rectangle()
                .frame(maxWidth: .infinity, maxHeight: .infinity)
                .foregroundColor(Color(UIColor(red: 0.89, green: 0.92, blue: 0.93, alpha: 1.00)))
                .edgesIgnoringSafeArea(.all)
            RoundedRectangle(cornerRadius: 10)
                .frame(width: 200, height:200)
                .offset(x: -40, y: -40)
                .shadow(color: Color(red: 0.7, green: 0.7, blue: 0.7),
                        radius: 20, x: -1, y: 30)
            RoundedRectangle(cornerRadius: 10)
                .frame(width: 200, height:200)
                .foregroundColor(Color(UIColor(red: 0.94, green: 0.95, blue: 0.96, alpha: 1.00)))
                .offset(x: 40, y: 40)
                .shadow(color: Color(red: 0.8, green: 0.8, blue: 0.8),
                        radius: 12, x: -0.50, y: 20)
            RoundedRectangle(cornerRadius: 10)
                .frame(width: 200, height:200)
                .offset(x: -40, y: -40)
                .shadow(color: Color(red: 0.8, green: 0.8, blue: 0.8),
                        radius: 6, x: -2, y: 6)
                .mask(BottomRectangleMask())
            RoundedRectangle(cornerRadius: 10)
                .frame(width: 200, height:200)
                .foregroundColor(.white)
                .offset(x: -40, y: -40)
        }
    }
    struct BottomRectangleMask: View {
        var body: some View {
            RoundedRectangle(cornerRadius: 10)
            .frame(width: 200, height:200)
            .offset(x: 40, y: 40)
        }
    }
}

Screenshot:

I think the bottom shadow radius needs tweaking (the lighting doesn't seem right), but this gives a rough draft idea of the concept. The key here being the BottomRectangleMask(). Here is a screenshot making the mask more obvious: