Swift 如何在 ZStack 中单独下移卡片

我在ZStack中有一副卡片组，我想一张张地向下移动纸牌.我正在努力实现这一点，当移动的卡片触底时，即将到来的卡片应该开始向下移动.我面临的问题是，整个ZStack正在向下移动，而不是一张卡.

import SwiftUI

struct Card: Identifiable {
    
    let id = UUID()
    let color: Color
    let name: String
}

struct CardView: View {
    
    let card: Card
        
    var body: some View {
        Rectangle()
            .fill(card.color)
            .frame(width: 120, height: 120)
            .cornerRadius(10)
            .overlay(
                Text(card.name)
                    .font(.headline)
                    .foregroundColor(.white)
            )
    }
}

struct ContentView: View {
    var cards: [Card] = [
        Card(color: Color.red, name: "First Card"),
        Card(color: Color.green, name: "Second Card"),
        Card(color: Color.orange, name: "Third Card"),
    ]
    
    @State var timer = Timer.publish(every: 0.1, on: .main, in: .common).autoconnect()
    @State var movingDownSpeed = CGPoint(x: 0, y:10)
    @State var cardPosition = CGPoint(x: UIScreen.main.bounds.size.width * 0.5, y:75)

 
    var body: some View {
        
        ZStack {
            ForEach(cards) { card in
               CardView(card: card)
                    .position(cardPosition)
                    .onReceive(self.timer) { _ in
                        moveDown()
                    }
            }
        }
        
    }
    
    func moveDown() {
        if cardPosition.y < UIScreen.main.bounds.height - 120 {
            withAnimation(.default){
                cardPosition.y += movingDownSpeed.y
            }
        }
    }
    
}