diff --git a/src/TextForge.Core/Documents/Document.cs b/src/TextForge.Core/Documents/Document.cs
index fecbc66..1363477 100644
--- a/src/TextForge.Core/Documents/Document.cs
+++ b/src/TextForge.Core/Documents/Document.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using TextForge.Core.Modules;
 
 namespace TextForge.Core.Documents;
@@ -12,7 +13,7 @@ public class Document
     public Guid Id { get; init; } = Guid.NewGuid();
     public DocumentMetadata Metadata { get; set; } = new();
     public string TemplateName { get; set; } = "Default";
-    public List<Module> Modules { get; init; } = [];
+    public ObservableCollection<Module> Modules { get; init; } = [];
 
     /// <summary>
     /// Currently selected module in the active editing session, if any.
@@ -39,7 +40,10 @@ public Document(DocumentMetadata metadata, IEnumerable<Module>? modules = null,
         TemplateName = templateName;
         if (modules is not null)
         {
-            Modules.AddRange(modules);
+            foreach (var module in modules)
+            {
+                Modules.Add(module);
+            }
         }
     }
 
@@ -55,7 +59,8 @@ public void NotifyChanged()
 
     /// <summary>
     /// Adds a module to the document hierarchy.
-    /// If parent is provided, appends to parent.SubModules; otherwise appends to root Modules.
+    /// If parent is provided, appends to parent.SubModules, expands parent, and keeps parent selected.
+    /// If parent is null, appends to root Modules and selects the new module.
     /// </summary>
     /// <param name="newModule">The module to insert.</param>
     /// <param name="parent">The target parent module, or null to append to the document root.</param>
@@ -66,19 +71,23 @@ public Document AddModule(Module newModule, Module? parent = null)
 
         if (parent is not null)
         {
+            // Auto-expand the parent so the newly added child is visible
+            parent.IsExpanded = true;
             parent.SubModules.Add(newModule);
+
+            // Retain selection on the existing parent
+            SelectModule(parent);
         }
         else
         {
             Modules.Add(newModule);
+            // Root addition: select the newly created root module
+            SelectModule(newModule);
         }
 
-        // Keep the newly added module active for selection/toolbar
-        SelectModule(newModule);
         NotifyChanged();
         return this;
     }
-    
     /// <summary>
     /// Updates the active module selection, updating all node flags across the tree.
     /// </summary>
diff --git a/src/TextForge.Core/Modules/Module.cs b/src/TextForge.Core/Modules/Module.cs
index d9fac76..81ac634 100644
--- a/src/TextForge.Core/Modules/Module.cs
+++ b/src/TextForge.Core/Modules/Module.cs
@@ -1,6 +1,8 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
+using System.ComponentModel;
+using System.Runtime.CompilerServices;
 
 namespace TextForge.Core.Modules;
 
@@ -8,40 +10,64 @@ namespace TextForge.Core.Modules;
 /// Represents an independent content element within a document.
 /// Modules can be nested hierarchically to form compound structures.
 /// </summary>
-public class Module
+public class Module : INotifyPropertyChanged
 {
+    private string _content = string.Empty;
+    private bool _isSelected;
+    private bool _isExpanded;
+
+    public event PropertyChangedEventHandler? PropertyChanged;
+
     public Guid Id { get; init; } = Guid.NewGuid();
 
-    /// <summary>
-    /// Archetype identifier used for preset styling and UI representation (e.g., "default-title").
-    /// </summary>
     public string Name { get; set; } = "default-text";
 
-    /// <summary>
-    /// Optional key corresponding to a template style rule (e.g., "Title", "Heading", "Body").
-    /// </summary>
     public string? StyleKey { get; init; }
 
     public ModuleType Type { get; init; } = ModuleType.Text;
 
-    public string Content { get; set; } = string.Empty;
-
+    public string Content
+    {
+        get => _content;
+        set
+        {
+            if (_content != value)
+            {
+                _content = value;
+                OnPropertyChanged();
+            }
+        }
+    }
 
-    /// <summary>
-    /// Direct visual overrides that take precedence over the template style.
-    /// </summary>
     public ModuleFeatures Features { get; set; } = ModuleFeatures.Default;
 
-    /// <summary>
-    /// Nested child modules (e.g., list items under a section heading).
-    /// </summary>
     public ObservableCollection<Module> SubModules { get; set; } = [];
 
+    public bool IsSelected
+    {
+        get => _isSelected;
+        set
+        {
+            if (_isSelected != value)
+            {
+                _isSelected = value;
+                OnPropertyChanged();
+            }
+        }
+    }
 
-    /// <summary>
-    /// Ephemeral UI selection state. Retained in-memory during active sessions.
-    /// </summary>
-    public bool IsSelected { get; set; }
+    public bool IsExpanded
+    {
+        get => _isExpanded;
+        set
+        {
+            if (_isExpanded != value)
+            {
+                _isExpanded = value;
+                OnPropertyChanged();
+            }
+        }
+    }
 
     public Module() { }
 
@@ -59,41 +85,28 @@ public Module(
         Name = name;
     }
 
+    protected void OnPropertyChanged([CallerMemberName] string? propertyName = null)
+    {
+        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+    }
+
     #region Archetype Presets
 
-    /// <summary>
-    /// Creates a top-level document title module.
-    /// </summary>
     public static Module CreateTitle(string text) =>
         new(text, ModuleType.Section, styleKey: "Title", name: "default-title");
 
-    /// <summary>
-    /// Creates a section header module.
-    /// </summary>
     public static Module CreateHeading(string text) =>
         new(text, ModuleType.Section, styleKey: "Heading", name: "default-heading");
 
-    /// <summary>
-    /// Creates a standard body paragraph module.
-    /// </summary>
     public static Module CreateParagraph(string text) =>
         new(text, ModuleType.Text, styleKey: "Body", name: "default-paragraph");
 
-    /// <summary>
-    /// Creates a bullet item module with prefixed bullet character.
-    /// </summary>
     public static Module CreateBulletItem(string text) =>
         new($"• {text.TrimStart('•', ' ')}", ModuleType.Text, styleKey: "Body", name: "default-bullet");
 
-    /// <summary>
-    /// Creates an accent callout banner module.
-    /// </summary>
     public static Module CreateCallout(string text) =>
         new(text, ModuleType.Text, styleKey: "Callout", name: "default-callout");
 
-    /// <summary>
-    /// Creates an alert module with explicit color and weight overrides.
-    /// </summary>
     public static Module CreateAlert(string text, string color = "#DC2626") =>
         new(text, ModuleType.Text, features: new ModuleFeatures
         {
diff --git a/src/TextForge.Desktop/Views/Components/ModuleEditorView.axaml b/src/TextForge.Desktop/Views/Components/ModuleEditorView.axaml
index 84d5682..700349d 100644
--- a/src/TextForge.Desktop/Views/Components/ModuleEditorView.axaml
+++ b/src/TextForge.Desktop/Views/Components/ModuleEditorView.axaml
@@ -27,7 +27,7 @@
             </Setter>
         </Style>
 
-        <!-- Active Selected Card State (Unified for root & nested) -->
+        <!-- Active Selected Card State (Unified across all depths) -->
         <Style Selector="Border.module-card.selected">
             <Setter Property="Background" Value="#EFF6FF" />
             <Setter Property="BorderBrush" Value="#2563EB" />
@@ -35,117 +35,79 @@
         </Style>
     </UserControl.Styles>
 
-    <ScrollViewer VerticalScrollBarVisibility="Auto"
-                  HorizontalScrollBarVisibility="Disabled">
-        <ListBox Name="ModuleListBox"
-                 Background="Transparent"
-                 SelectionMode="Single">
-            <ListBox.ItemTemplate>
-                <DataTemplate x:DataType="mod:Module">
-                    <!-- Root Module Card -->
-                    <Border Classes="module-card"
-                            Tag="{Binding}"
-                            Margin="0,1"
-                            Padding="2">
-                        <Expander IsExpanded="False"
-                                  HorizontalAlignment="Stretch"
-                                  Background="Transparent">
-                            <Expander.Header>
-                                <Grid ColumnDefinitions="Auto,*,Auto"
-                                      VerticalAlignment="Center"
-                                      Background="Transparent">
-                                    <!-- Archetype Tag -->
-                                    <Border Grid.Column="0"
-                                            Background="#E5E7EB"
-                                            CornerRadius="4"
-                                            Padding="6,2"
-                                            Margin="0,0,8,0">
-                                        <TextBlock Text="{Binding Name}"
-                                                   FontSize="11"
-                                                   FontWeight="SemiBold"
-                                                   Foreground="#374151" />
-                                    </Border>
+    <UserControl.Resources>
+        <!-- Self-Referencing Recursive Template for Modules & Submodules at any depth -->
+        <DataTemplate x:Key="RecursiveModuleTemplate" x:DataType="mod:Module">
+            <Border Classes="module-card"
+                    Tag="{Binding}"
+                    Margin="0,1"
+                    Padding="2">
+                <Expander IsExpanded="{Binding IsExpanded, Mode=TwoWay, FallbackValue=False}"
+                          HorizontalAlignment="Stretch"
+                          Background="Transparent">
+                    <Expander.Header>
+                        <Grid ColumnDefinitions="Auto,*,Auto"
+                              VerticalAlignment="Center"
+                              Background="Transparent">
+                            <!-- Archetype Tag -->
+                            <Border Grid.Column="0"
+                                    Background="#E5E7EB"
+                                    CornerRadius="4"
+                                    Padding="6,2"
+                                    Margin="0,0,8,0">
+                                <TextBlock Text="{Binding Name}"
+                                           FontSize="11"
+                                           FontWeight="SemiBold"
+                                           Foreground="#374151" />
+                            </Border>
 
-                                    <!-- Content Preview -->
-                                    <TextBlock Grid.Column="1"
-                                               Text="{Binding Content}"
-                                               TextTrimming="CharacterEllipsis"
-                                               VerticalAlignment="Center"
-                                               FontSize="12"
-                                               Foreground="#1F2937" />
+                            <!-- Content Preview -->
+                            <TextBlock Grid.Column="1"
+                                       Text="{Binding Content}"
+                                       TextTrimming="CharacterEllipsis"
+                                       VerticalAlignment="Center"
+                                       FontSize="12"
+                                       Foreground="#1F2937" />
 
-                                    <!-- Action Buttons -->
-                                    <StackPanel Grid.Column="2" Orientation="Horizontal" Spacing="2" Margin="4,0,0,0">
-                                        <Button Content="▲" FontSize="10" Width="22" Height="22" Padding="0"
-                                                HorizontalContentAlignment="Center" VerticalContentAlignment="Center"
-                                                Background="Transparent" Foreground="#6B7280" ToolTip.Tip="Move Up"
-                                                Tag="{Binding}" Click="MoveUpButton_Click" />
-                                        <Button Content="▼" FontSize="10" Width="22" Height="22" Padding="0"
-                                                HorizontalContentAlignment="Center" VerticalContentAlignment="Center"
-                                                Background="Transparent" Foreground="#6B7280" ToolTip.Tip="Move Down"
-                                                Tag="{Binding}" Click="MoveDownButton_Click" />
-                                        <Button Content="✕" FontSize="11" Width="22" Height="22" Padding="0"
-                                                HorizontalContentAlignment="Center" VerticalContentAlignment="Center"
-                                                Background="Transparent" Foreground="#EF4444" ToolTip.Tip="Delete Module"
-                                                Tag="{Binding}" Click="DeleteModuleButton_Click" />
-                                    </StackPanel>
-                                </Grid>
-                            </Expander.Header>
+                            <!-- Action Buttons -->
+                            <StackPanel Grid.Column="2" Orientation="Horizontal" Spacing="2" Margin="4,0,0,0">
+                                <Button Content="▲" FontSize="10" Width="22" Height="22" Padding="0"
+                                        HorizontalContentAlignment="Center" VerticalContentAlignment="Center"
+                                        Background="Transparent" Foreground="#6B7280" ToolTip.Tip="Move Up"
+                                        Tag="{Binding}" Click="MoveUpButton_Click" />
+                                <Button Content="▼" FontSize="10" Width="22" Height="22" Padding="0"
+                                        HorizontalContentAlignment="Center" VerticalContentAlignment="Center"
+                                        Background="Transparent" Foreground="#6B7280" ToolTip.Tip="Move Down"
+                                        Tag="{Binding}" Click="MoveDownButton_Click" />
+                                <Button Content="✕" FontSize="11" Width="22" Height="22" Padding="0"
+                                        HorizontalContentAlignment="Center" VerticalContentAlignment="Center"
+                                        Background="Transparent" Foreground="#EF4444" ToolTip.Tip="Delete Module"
+                                        Tag="{Binding}" Click="DeleteModuleButton_Click" />
+                            </StackPanel>
+                        </Grid>
+                    </Expander.Header>
 
-                            <StackPanel Spacing="6" Margin="4,6,4,4">
-                                <TextBox Text="{Binding Content, Mode=TwoWay}"
-                                         AcceptsReturn="True"
-                                         TextWrapping="Wrap"
-                                         MinHeight="55" />
+                    <StackPanel Spacing="6" Margin="4,6,4,4">
+                        <TextBox Text="{Binding Content, Mode=TwoWay}"
+                                 AcceptsReturn="True"
+                                 TextWrapping="Wrap"
+                                 MinHeight="45" />
 
-                                <!-- Nested Submodules (Recursive) -->
-                                <ItemsControl ItemsSource="{Binding SubModules}" Margin="14,2,0,0">
-                                    <ItemsControl.ItemTemplate>
-                                        <DataTemplate x:DataType="mod:Module">
-                                            <Border Classes="module-card"
-                                                    Tag="{Binding}"
-                                                    Margin="0,2,0,2"
-                                                    Padding="2">
-                                                <Expander IsExpanded="False" Background="Transparent">
-                                                    <Expander.Header>
-                                                        <Grid ColumnDefinitions="Auto,*,Auto"
-                                                              VerticalAlignment="Center"
-                                                              Background="Transparent">
-                                                            <Border Grid.Column="0" Background="#E5E7EB" CornerRadius="3" Padding="4,1" Margin="0,0,6,0">
-                                                                <TextBlock Text="{Binding Name}" FontSize="10" FontWeight="Medium" Foreground="#4B5563" />
-                                                            </Border>
-                                                            <TextBlock Grid.Column="1" Text="{Binding Content}" FontSize="11" TextTrimming="CharacterEllipsis" />
-                                                            <StackPanel Grid.Column="2" Orientation="Horizontal" Spacing="2" Margin="4,0,0,0">
-                                                                <Button Content="▲" FontSize="9" Width="20" Height="20" Padding="0"
-                                                                        HorizontalContentAlignment="Center" VerticalContentAlignment="Center"
-                                                                        Background="Transparent" Foreground="#6B7280" ToolTip.Tip="Move Up"
-                                                                        Tag="{Binding}" Click="MoveUpButton_Click" />
-                                                                <Button Content="▼" FontSize="9" Width="20" Height="20" Padding="0"
-                                                                        HorizontalContentAlignment="Center" VerticalContentAlignment="Center"
-                                                                        Background="Transparent" Foreground="#6B7280" ToolTip.Tip="Move Down"
-                                                                        Tag="{Binding}" Click="MoveDownButton_Click" />
-                                                                <Button Content="✕" FontSize="10" Width="20" Height="20" Padding="0"
-                                                                        HorizontalContentAlignment="Center" VerticalContentAlignment="Center"
-                                                                        Background="Transparent" Foreground="#EF4444" ToolTip.Tip="Delete Submodule"
-                                                                        Tag="{Binding}" Click="DeleteModuleButton_Click" />
-                                                            </StackPanel>
-                                                        </Grid>
-                                                    </Expander.Header>
-                                                    <TextBox Text="{Binding Content, Mode=TwoWay}"
-                                                             AcceptsReturn="True"
-                                                             TextWrapping="Wrap"
-                                                             MinHeight="40"
-                                                             Margin="2,4" />
-                                                </Expander>
-                                            </Border>
-                                        </DataTemplate>
-                                    </ItemsControl.ItemTemplate>
-                                </ItemsControl>
-                            </StackPanel>
-                        </Expander>
-                    </Border>
-                </DataTemplate>
-            </ListBox.ItemTemplate>
-        </ListBox>
+                        <!-- Recursive ItemsControl: uses the exact same template for child submodules -->
+                        <ItemsControl ItemsSource="{Binding SubModules}"
+                                      ItemTemplate="{StaticResource RecursiveModuleTemplate}"
+                                      Margin="14,2,0,0" />
+                    </StackPanel>
+                </Expander>
+            </Border>
+        </DataTemplate>
+    </UserControl.Resources>
+
+    <ScrollViewer VerticalScrollBarVisibility="Auto"
+                  HorizontalScrollBarVisibility="Disabled">
+        <ListBox Name="ModuleListBox"
+                 Background="Transparent"
+                 SelectionMode="Single"
+                 ItemTemplate="{StaticResource RecursiveModuleTemplate}" />
     </ScrollViewer>
 </UserControl>
diff --git a/src/TextForge.Desktop/Views/Components/ModuleEditorView.axaml.cs b/src/TextForge.Desktop/Views/Components/ModuleEditorView.axaml.cs
index 93e82a6..5fad44b 100644
--- a/src/TextForge.Desktop/Views/Components/ModuleEditorView.axaml.cs
+++ b/src/TextForge.Desktop/Views/Components/ModuleEditorView.axaml.cs
@@ -5,24 +5,10 @@
 
 namespace TextForge.Desktop.Views.Components;
 
-/// <summary>
-/// Module editor accordion tree presenting root and nested document modules.
-/// </summary>
 public partial class ModuleEditorView : UserControl
 {
-    /// <summary>
-    /// Raised when a user requests moving a module up within its level.
-    /// </summary>
     public event EventHandler<Module>? ModuleMoveUpRequested;
-
-    /// <summary>
-    /// Raised when a user requests moving a module down within its level.
-    /// </summary>
     public event EventHandler<Module>? ModuleMoveDownRequested;
-
-    /// <summary>
-    /// Raised when a user clicks the delete button for a specific module node.
-    /// </summary>
     public event EventHandler<Module>? ModuleDeleteRequested;
 
     public ModuleEditorView()
@@ -35,7 +21,6 @@ private void MoveUpButton_Click(object? sender, RoutedEventArgs e)
         if (sender is Button { Tag: Module module })
         {
             ModuleMoveUpRequested?.Invoke(this, module);
-            e.Handled = true;
         }
     }
 
@@ -44,7 +29,6 @@ private void MoveDownButton_Click(object? sender, RoutedEventArgs e)
         if (sender is Button { Tag: Module module })
         {
             ModuleMoveDownRequested?.Invoke(this, module);
-            e.Handled = true;
         }
     }
 
@@ -53,7 +37,6 @@ private void DeleteModuleButton_Click(object? sender, RoutedEventArgs e)
         if (sender is Button { Tag: Module module })
         {
             ModuleDeleteRequested?.Invoke(this, module);
-            e.Handled = true;
         }
     }
 }
diff --git a/src/TextForge.Desktop/Views/MainWindow.axaml.cs b/src/TextForge.Desktop/Views/MainWindow.axaml.cs
index b2ad873..4e5bd71 100644
--- a/src/TextForge.Desktop/Views/MainWindow.axaml.cs
+++ b/src/TextForge.Desktop/Views/MainWindow.axaml.cs
@@ -404,8 +404,6 @@ private void PaletteItem_Click(object? sender, RoutedEventArgs e)
             // 3. Refresh the ModuleEditor ListBox ItemsSource to show the new module
             RefreshModuleEditorList();
 
-            // 4. Select the newly added module
-            _currentDocument.SelectModule(newModule);
             SyncPropertiesToolbar(newModule);
         }
     }