Thank you very much, it seems to be working. You have helped me a lot. Here is the code, what do you think?

import SwiftUI

struct SettingsView: View {
    @FocusState private var selectedCategory: String?

    var body: some View {
        NavigationStack {
            ZStack {
                Color.black
                    .edgesIgnoringSafeArea(.all)

                VStack(spacing: 0) {
                    // Überschrift oben in der Mitte
                    Text("Einstellungen")
                        .font(.system(size: 40, weight: .semibold))
                        .foregroundColor(.white)
                        .padding(.top, 30)

                    HStack {
                        
                        VStack {
                            Spacer()
                            Image(systemName: "applelogo")
                                .resizable()
                                .scaledToFit()
                                .frame(width: 120, height: 120)
                                .foregroundColor(.white)
                            Spacer()
                        }
                        .frame(width: UIScreen.main.bounds.width * 0.4)

                        // Rechte Seite mit Kategorien
                        VStack(spacing: 15) {
                            ForEach(categories, id: \.self) { category in
                                NavigationLink(value: category) {
                                    SettingsCategoryView(title: category)
                                }
                                .focused($selectedCategory, equals: category)
                                .buttonStyle(SettingsViewButtonStyle(
                                    isSelected: selectedCategory == category
                                ))
                            }
                        }
                        .frame(width: UIScreen.main.bounds.width * 0.5)
                    }
                }
            }
            .navigationDestination(for: String.self) { value in
                Text("\(value)-Ansicht")
                    .font(.title)
                    .foregroundColor(.white)
                    .navigationTitle(value)
            }
        }
    }

    private var categories: [String] {
        ["Allgemein", "Benutzer:innen und Accounts", "Video und Audio", "Bildschirmschoner", "AirPlay und HomeKit", "Fernbedienungen und Geräte", "Apps", "Netzwerk", "System", "Entwickler"]
    }
}

struct SettingsViewButtonStyle: ButtonStyle {
    let isSelected: Bool

    func makeBody(configuration: Configuration) -> some View {
        configuration.label
            .foregroundStyle(isSelected ? .black : .white)
            .padding(.horizontal, 20)
            .frame(height: 50)
            .background {
                RoundedRectangle(cornerRadius: 8)
                    .fill(isSelected ? .white : .gray.opacity(0.3))
            }
            .scaleEffect(isSelected ? 1.05 : 1.0)
            .animation(.easeInOut, value: isSelected)
    }
}

struct SettingsCategoryView: View {
    let title: String

    var body: some View {
        HStack {
            Text(title)
                .font(.system(size: 22, weight: .medium))

            Spacer()

            Image(systemName: "chevron.right")
                .foregroundStyle(.gray)
        }
    }
}

struct SettingsView_Previews: PreviewProvider {
    static var previews: some View {
        SettingsView()
    }
}