struct AdaptiveView: View {
    @Environment(\.horizontalSizeClass) var sizeClass

    var body: some View {
        if sizeClass == .regular {
            TwoColumnLayout()
        } else {
            StackedLayout()
        }
    }
}

struct ThreeColumnLayout: View {
    var body: some View {
        NavigationSplitView {
            SidebarView()
        } content: {
            ContentListView()
        } detail: {
            DetailView()
        }
    }
}

@main
struct MyApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
        // Support multiple windows
        WindowGroup("Detail", for: Item.ID.self) { $itemId in
            DetailView(itemId: itemId)
        }
    }
}

struct AppNavigation: View {
    @State private var selection: NavigationItem? = .inbox

    var body: some View {
        NavigationSplitView {
            List(selection: $selection) {
                Section("Main") {
                    Label("Inbox", systemImage: "tray")
                        .tag(NavigationItem.inbox)
                    Label("Drafts", systemImage: "doc")
                        .tag(NavigationItem.drafts)
                    Label("Sent", systemImage: "paperplane")
                        .tag(NavigationItem.sent)
                }
                Section("Labels") {
                    // Dynamic sections
                }
            }
            .navigationTitle("Mail")
        } detail: {
            DetailView(for: selection)
        }
    }
}

TabView {
    Tab("Home", systemImage: "house") { HomeView() }
    Tab("Search", systemImage: "magnifyingglass") { SearchView() }
    Tab("Profile", systemImage: "person") { ProfileView() }
}
.tabViewStyle(.sidebarAdaptable)

.toolbar {
    ToolbarItemGroup(placement: .primaryAction) {
        Button("Compose", systemImage: "square.and.pencil") { }
    }
    ToolbarItemGroup(placement: .secondaryAction) {
        Button("Archive", systemImage: "archivebox") { }
        Button("Delete", systemImage: "trash") { }
    }
}

Button("Action") { }
    .hoverEffect(.highlight)  // Subtle highlight on hover

// Custom hover effect
MyCustomView()
    .hoverEffect(.lift)  // Lifts and adds shadow

Text(item.title)
    .contextMenu {
        Button("Copy", systemImage: "doc.on.doc") { }
        Button("Share", systemImage: "square.and.arrow.up") { }
        Divider()
        Button("Delete", systemImage: "trash", role: .destructive) { }
    }

Button("New Document") { createDocument() }
    .keyboardShortcut("n", modifiers: .command)

struct FormView: View {
    @FocusState private var focusedField: Field?

    var body: some View {
        Form {
            TextField("Name", text: $name)
                .focused($focusedField, equals: .name)
            TextField("Email", text: $email)
                .focused($focusedField, equals: .email)
            TextField("Phone", text: $phone)
                .focused($focusedField, equals: .phone)
        }
    }
}

// UIKit hover support
override func pencilHoverChanged(_ hover: UIHoverGestureRecognizer) {
    let location = hover.location(in: canvas)
    showBrushPreview(at: location)
}

import PencilKit

struct DrawingView: UIViewRepresentable {
    @Binding var canvasView: PKCanvasView

    func makeUIView(context: Context) -> PKCanvasView {
        canvasView.tool = PKInkingTool(.pen, color: .black, width: 5)
        canvasView.drawingPolicy = .anyInput
        return canvasView
    }
}

// As drag source
Text(item.title)
    .draggable(item.title)

// As drop destination
DropTarget()
    .dropDestination(for: String.self) { items, location in
        handleDrop(items)
        return true
    }

struct ReorderDropDelegate: DropDelegate {
    let item: Item
    @Binding var items: [Item]
    @Binding var draggedItem: Item?

    func performDrop(info: DropInfo) -> Bool {
        draggedItem = nil
        return true
    }

    func dropEntered(info: DropInfo) {
        guard let draggedItem,
              let fromIndex = items.firstIndex(of: draggedItem),
              let toIndex = items.firstIndex(of: item) else { return }
        withAnimation {
            items.move(fromOffsets: IndexSet(integer: fromIndex),
                      toOffset: toIndex > fromIndex ? toIndex + 1 : toIndex)
        }
    }
}

@main
struct MyApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
        // Additional scene for external display
        WindowGroup(id: "presentation") {
            PresentationView()
        }
    }
}