Added Minimize/Maximize/Close Buttons and took WindowStyle

ViewModels/MainWindowViewModel.cs

@@ -13,6 +13,9 @@ public class MainWindowViewModel : ViewModelBase
     public MainWindowViewModel()
     {
         DisplaySplitEvent = new RelayCommand(DisplaySplit);
+        CloseAppEvent = new RelayCommand(CloseApp);
+        MaximizeAppEvent = new RelayCommand(MaximizeApp);
+        MinimizeAppEvent = new RelayCommand(MinimizeApp);
 
         ColorPalette =
         [

ViewModels/ViewModelBase.cs

@@ -74,4 +74,33 @@ public class ViewModelBase : ObservableObject
     {
         IsSplitOpen = !IsSplitOpen;
     }
+
+    private WindowState _windowStateProperty;
+
+    public WindowState WindowStateProperty
+    {
+        get => _windowStateProperty;
+        set => SetProperty(ref _windowStateProperty, value);
+    }
+
+    public IRelayCommand CloseAppEvent { get; protected set; }
+
+    protected void CloseApp()
+    {
+        Environment.Exit(0);
+    }
+
+    public IRelayCommand MaximizeAppEvent { get; protected set; }
+
+    protected void MaximizeApp()
+    {
+        WindowStateProperty = WindowState.Maximized;
+    }
+
+    public IRelayCommand MinimizeAppEvent { get; protected set; }
+
+    protected void MinimizeApp()
+    {
+        WindowStateProperty = WindowState.Minimized;
+    }
 }