使用SwitftUI，我如何改变文本的字体大小？

import SwiftUI

struct ContentView: View {
    @State private var fontSize: CGFloat = 16
    
    var body: some View {
        VStack {
            Text("Hello, SwiftUI!")
                .font(Font.system(size: fontSize))
            
            Slider(value: $fontSize, in: 12...24, step: 1)
                .padding()
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}