refactoring

UI/MainWindow.axaml.cs

@@ -0,0 +1,23 @@
+using Avalonia.Controls;
+using Avalonia.Styling;
+
+namespace MercuryConverter.UI;
+
+using MercuryConverter.UI.Views;
+
+public partial class MainWindow : Window
+{
+    public MainWindow()
+    {
+        InitializeComponent();
+
+        // Force dark mode in designer
+        if (Design.IsDesignMode)
+        {
+            RequestedThemeVariant = ThemeVariant.Dark;
+        }
+
+        // Setup tab views
+        SelectionControl.Content = new Selection();
+    }
+}