diff --git a/src/ClaudeDo.Localization/locales/de.json b/src/ClaudeDo.Localization/locales/de.json
index 8e0bb45..cf35ead 100644
--- a/src/ClaudeDo.Localization/locales/de.json
+++ b/src/ClaudeDo.Localization/locales/de.json
@@ -192,6 +192,11 @@
       "overLimitError": "Konnte {0} nicht hinzufügen: {1}",
       "invalidNameError": "Konnte {0} nicht hinzufügen: {1}",
       "selectIdleTask": "Zuerst eine inaktive Aufgabe auswählen"
+    },
+    "sections": {
+      "description": "Beschreibung",
+      "steps": "Schritte",
+      "files": "Dateien"
     }
   },
   "agent": {
diff --git a/src/ClaudeDo.Localization/locales/en.json b/src/ClaudeDo.Localization/locales/en.json
index 16f16c0..1786344 100644
--- a/src/ClaudeDo.Localization/locales/en.json
+++ b/src/ClaudeDo.Localization/locales/en.json
@@ -192,6 +192,11 @@
       "overLimitError": "Could not add {0}: {1}",
       "invalidNameError": "Could not add {0}: {1}",
       "selectIdleTask": "Select an idle task first"
+    },
+    "sections": {
+      "description": "Description",
+      "steps": "Steps",
+      "files": "Files"
     }
   },
   "agent": {
diff --git a/src/ClaudeDo.Ui/ViewModels/Islands/DetailsIslandViewModel.cs b/src/ClaudeDo.Ui/ViewModels/Islands/DetailsIslandViewModel.cs
index 6a1e613..2fac4db 100644
--- a/src/ClaudeDo.Ui/ViewModels/Islands/DetailsIslandViewModel.cs
+++ b/src/ClaudeDo.Ui/ViewModels/Islands/DetailsIslandViewModel.cs
@@ -117,23 +117,30 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
     [RelayCommand]
     private void ToggleDescriptionExpanded() => IsDescriptionExpanded = !IsDescriptionExpanded;
 
-    [ObservableProperty] private bool _isStepsExpanded;
+    // Which section of the details card is shown (header acts as a segment switcher).
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(IsDescriptionSection))]
+    [NotifyPropertyChangedFor(nameof(IsStepsSection))]
+    [NotifyPropertyChangedFor(nameof(IsFilesSection))]
+    private string _detailSection = "description";
+
+    public bool IsDescriptionSection => DetailSection == "description";
+    public bool IsStepsSection       => DetailSection == "steps";
+    public bool IsFilesSection       => DetailSection == "files";
 
     [RelayCommand]
-    private void ToggleStepsExpanded() => IsStepsExpanded = !IsStepsExpanded;
+    private void SelectDetailSection(string? section) => DetailSection = section ?? "description";
 
     public int TotalStepCount => Subtasks.Count;
-    public int OpenStepCount => Subtasks.Count(s => !s.Done);
-    public string StepsSummary =>
-        TotalStepCount == 0 ? "no steps yet"
-        : OpenStepCount == 0 ? $"all done · {TotalStepCount} total"
-        : $"{OpenStepCount} open · {TotalStepCount} total";
+    public int DoneStepCount => Subtasks.Count(s => s.Done);
+    public string StepsBadge => TotalStepCount > 0 ? $"{DoneStepCount}/{TotalStepCount}" : "";
+    public string FilesBadge => Attachments.Count > 0 ? Attachments.Count.ToString() : "";
 
     private void NotifyStepsChanged()
     {
         OnPropertyChanged(nameof(TotalStepCount));
-        OnPropertyChanged(nameof(OpenStepCount));
-        OnPropertyChanged(nameof(StepsSummary));
+        OnPropertyChanged(nameof(DoneStepCount));
+        OnPropertyChanged(nameof(StepsBadge));
         OnPropertyChanged(nameof(ComposedPreview));
     }
 
@@ -425,6 +432,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         Notes = new NotesEditorViewModel(_notesApi);
         Subtasks.CollectionChanged += (_, _) => NotifyStepsChanged();
         Subtasks.CollectionChanged += (_, _) => Merge.SyncChildOutcomes(HasChildOutcomes, Subtasks.Count);
+        Attachments.CollectionChanged += (_, _) => OnPropertyChanged(nameof(FilesBadge));
 
         AgentSettings.PropertyChanged += (_, e) =>
         {
@@ -1233,6 +1241,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
 
     public async System.Threading.Tasks.Task AddFilesAsync(IReadOnlyList<(string FileName, Stream Content)> files)
     {
+        DetailSection = "files";
         if (Task is null || Task.IsRunning)
         {
             DropStatus = Loc.T("details.attachments.selectIdleTask");
diff --git a/src/ClaudeDo.Ui/Views/Islands/Detail/DescriptionStepsCard.axaml b/src/ClaudeDo.Ui/Views/Islands/Detail/DescriptionStepsCard.axaml
index 78bc9d1..16d4c07 100644
--- a/src/ClaudeDo.Ui/Views/Islands/Detail/DescriptionStepsCard.axaml
+++ b/src/ClaudeDo.Ui/Views/Islands/Detail/DescriptionStepsCard.axaml
@@ -6,17 +6,70 @@
              x:Class="ClaudeDo.Ui.Views.Islands.Detail.DescriptionStepsCard"
              x:DataType="vm:DetailsIslandViewModel">
 
+  <UserControl.Styles>
+    <!-- Segment switcher in the card header (mirrors the WorkConsole tab look) -->
+    <Style Selector="Button.seg-btn">
+      <Setter Property="Background"      Value="Transparent" />
+      <Setter Property="BorderThickness" Value="0" />
+      <Setter Property="Padding"         Value="8,3" />
+      <Setter Property="CornerRadius"    Value="6" />
+      <Setter Property="FontFamily"      Value="{StaticResource MonoFont}" />
+      <Setter Property="FontSize"        Value="{StaticResource FontSizeMono}" />
+      <Setter Property="Foreground"      Value="{StaticResource TextMuteBrush}" />
+      <Setter Property="Cursor"          Value="Hand" />
+    </Style>
+    <Style Selector="Button.seg-btn:pointerover /template/ ContentPresenter">
+      <Setter Property="Background"             Value="{StaticResource Surface2Brush}" />
+      <Setter Property="TextElement.Foreground" Value="{StaticResource TextDimBrush}" />
+    </Style>
+    <Style Selector="Button.seg-btn.active /template/ ContentPresenter">
+      <Setter Property="Background"             Value="{StaticResource Surface3Brush}" />
+      <Setter Property="TextElement.Foreground" Value="{StaticResource AccentBrush}" />
+    </Style>
+    <Style Selector="TextBlock.seg-count">
+      <Setter Property="Foreground" Value="{StaticResource TextMuteBrush}" />
+      <Setter Property="FontSize"   Value="{StaticResource FontSizeMono}" />
+    </Style>
+  </UserControl.Styles>
+
   <Border Classes="island"
           Background="{DynamicResource Surface2Brush}"
           BorderBrush="{DynamicResource LineBrush}">
     <DockPanel>
 
-      <!-- Header: DETAILS · copy · preview/edit -->
+      <!-- Header: segment switcher (Description · Steps · Files) + copy + edit -->
       <Border DockPanel.Dock="Top" Classes="island-header">
         <Grid ColumnDefinitions="Auto,*,Auto,Auto" VerticalAlignment="Center">
 
-          <TextBlock Grid.Column="0" Classes="section-label" Text="DETAILS"
-                     VerticalAlignment="Center"/>
+          <StackPanel Grid.Column="0" Orientation="Horizontal" Spacing="2">
+            <Button Classes="seg-btn"
+                    Classes.active="{Binding IsDescriptionSection}"
+                    Command="{Binding SelectDetailSectionCommand}"
+                    CommandParameter="description"
+                    Content="{loc:Tr details.sections.description}"/>
+            <Button Classes="seg-btn"
+                    Classes.active="{Binding IsStepsSection}"
+                    Command="{Binding SelectDetailSectionCommand}"
+                    CommandParameter="steps">
+              <StackPanel Orientation="Horizontal" Spacing="5">
+                <TextBlock Text="{loc:Tr details.sections.steps}" VerticalAlignment="Center"/>
+                <TextBlock Classes="seg-count" Text="{Binding StepsBadge}"
+                           VerticalAlignment="Center"
+                           IsVisible="{Binding StepsBadge, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+              </StackPanel>
+            </Button>
+            <Button Classes="seg-btn"
+                    Classes.active="{Binding IsFilesSection}"
+                    Command="{Binding SelectDetailSectionCommand}"
+                    CommandParameter="files">
+              <StackPanel Orientation="Horizontal" Spacing="5">
+                <TextBlock Text="{loc:Tr details.sections.files}" VerticalAlignment="Center"/>
+                <TextBlock Classes="seg-count" Text="{Binding FilesBadge}"
+                           VerticalAlignment="Center"
+                           IsVisible="{Binding FilesBadge, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+              </StackPanel>
+            </Button>
+          </StackPanel>
 
           <!-- Copy formatted -->
           <Button Grid.Column="2"
@@ -27,10 +80,11 @@
             <PathIcon Data="{StaticResource Icon.Copy}" Width="11" Height="11"/>
           </Button>
 
-          <!-- Preview/Edit toggle -->
+          <!-- Preview/Edit toggle (Description section only) -->
           <Button Grid.Column="3"
                   Classes="btn"
                   Padding="8,3"
+                  IsVisible="{Binding IsDescriptionSection}"
                   ToolTip.Tip="{loc:Tr details.toggleEditPreviewTip}"
                   Command="{Binding ToggleEditDescriptionCommand}">
             <Panel>
@@ -42,132 +96,101 @@
         </Grid>
       </Border>
 
-      <!-- Body (scrolls inside the card so the card fills its row to the divider) -->
+      <!-- Body: only the active section is shown -->
       <ScrollViewer VerticalScrollBarVisibility="Auto">
-      <StackPanel Margin="14" Spacing="10">
+        <Panel Margin="14">
 
-        <!-- Description (always visible) -->
-        <Panel>
-          <!-- Edit mode: raw TextBox -->
-          <TextBox Text="{Binding EditableDescription, Mode=TwoWay}"
-                   AcceptsReturn="True"
-                   TextWrapping="Wrap"
-                   MinHeight="80"
-                   MaxHeight="320"
-                   Padding="8"
-                   FontFamily="{DynamicResource MonoFont}"
-                   FontSize="{StaticResource FontSizeBody}"
-                   Background="{DynamicResource Surface3Brush}"
-                   BorderBrush="{DynamicResource LineBrush}"
-                   BorderThickness="1"
-                   CornerRadius="8"
-                   IsVisible="{Binding IsEditingDescription}"/>
-          <!-- Preview mode: rendered composed text (title + description + open steps) -->
-          <ctl:MarkdownView Markdown="{Binding ComposedPreview}"
-                            IsVisible="{Binding !IsEditingDescription}"/>
-        </Panel>
+          <!-- Description -->
+          <Panel IsVisible="{Binding IsDescriptionSection}">
+            <!-- Edit mode: raw TextBox -->
+            <TextBox Text="{Binding EditableDescription, Mode=TwoWay}"
+                     AcceptsReturn="True"
+                     TextWrapping="Wrap"
+                     MinHeight="80"
+                     MaxHeight="320"
+                     Padding="8"
+                     FontFamily="{DynamicResource MonoFont}"
+                     FontSize="{StaticResource FontSizeBody}"
+                     Background="{DynamicResource Surface3Brush}"
+                     BorderBrush="{DynamicResource LineBrush}"
+                     BorderThickness="1"
+                     CornerRadius="8"
+                     IsVisible="{Binding IsEditingDescription}"/>
+            <!-- Preview mode: rendered composed text (title + description + open steps) -->
+            <ctl:MarkdownView Markdown="{Binding ComposedPreview}"
+                              IsVisible="{Binding !IsEditingDescription}"/>
+          </Panel>
 
-        <!-- Steps: always-visible summary strip; expand to manage -->
-        <Border BorderBrush="{DynamicResource LineBrush}"
-                BorderThickness="0,1,0,0"
-                Padding="0,8,0,0">
-          <StackPanel Spacing="6">
+          <!-- Steps -->
+          <StackPanel IsVisible="{Binding IsStepsSection}" Spacing="6">
+            <TextBox Text="{Binding NewSubtaskTitle, Mode=TwoWay}"
+                     PlaceholderText="Add step…"
+                     Padding="8"
+                     Background="{DynamicResource Surface3Brush}"
+                     BorderBrush="{DynamicResource LineBrush}"
+                     BorderThickness="1"
+                     CornerRadius="8">
+              <TextBox.KeyBindings>
+                <KeyBinding Gesture="Enter" Command="{Binding AddSubtaskCommand}"/>
+              </TextBox.KeyBindings>
+            </TextBox>
 
-            <!-- Summary header (click to expand/collapse) -->
-            <Button Classes="flat" Cursor="Hand"
-                    HorizontalAlignment="Stretch"
-                    HorizontalContentAlignment="Stretch"
-                    Command="{Binding ToggleStepsExpandedCommand}">
-              <Grid ColumnDefinitions="Auto,Auto,*,Auto">
-                <Panel Grid.Column="0" Width="12" Margin="0,0,6,0" VerticalAlignment="Center">
-                  <TextBlock Classes="meta" Text="▸" IsVisible="{Binding !IsStepsExpanded}"/>
-                  <TextBlock Classes="meta" Text="▾" IsVisible="{Binding IsStepsExpanded}"/>
-                </Panel>
-                <TextBlock Grid.Column="1" Classes="section-label" Text="STEPS"
-                           VerticalAlignment="Center"/>
-                <TextBlock Grid.Column="3" Classes="meta" Text="{Binding StepsSummary}"
-                           Foreground="{DynamicResource TextMuteBrush}"
-                           VerticalAlignment="Center"/>
-              </Grid>
-            </Button>
+            <!-- Subtask rows -->
+            <ItemsControl ItemsSource="{Binding Subtasks}">
+              <ItemsControl.ItemTemplate>
+                <DataTemplate DataType="vm:SubtaskRowViewModel">
+                  <Border Classes="subtask-row" Classes.done="{Binding Done}">
+                    <Grid ColumnDefinitions="Auto,*">
 
-            <!-- Expanded: add-step input + step rows -->
-            <StackPanel IsVisible="{Binding IsStepsExpanded}" Spacing="6">
-              <TextBox Text="{Binding NewSubtaskTitle, Mode=TwoWay}"
-                       PlaceholderText="Add step…"
-                       Padding="8"
-                       Background="{DynamicResource Surface3Brush}"
-                       BorderBrush="{DynamicResource LineBrush}"
-                       BorderThickness="1"
-                       CornerRadius="8">
-                <TextBox.KeyBindings>
-                  <KeyBinding Gesture="Enter" Command="{Binding AddSubtaskCommand}"/>
-                </TextBox.KeyBindings>
-              </TextBox>
+                      <!-- Check circle -->
+                      <Button Grid.Column="0"
+                              Classes="flat"
+                              Padding="0"
+                              Margin="0,0,8,0"
+                              VerticalAlignment="Center"
+                              Command="{Binding $parent[ItemsControl].((vm:DetailsIslandViewModel)DataContext).ToggleSubtaskDoneCommand}"
+                              CommandParameter="{Binding}">
+                        <Ellipse Classes="task-check"
+                                 Classes.done="{Binding Done}"
+                                 Width="16" Height="16"
+                                 Cursor="Hand"/>
+                      </Button>
 
-              <!-- Subtask rows -->
-              <ItemsControl ItemsSource="{Binding Subtasks}">
-            <ItemsControl.ItemTemplate>
-              <DataTemplate DataType="vm:SubtaskRowViewModel">
-                <Border Classes="subtask-row" Classes.done="{Binding Done}">
-                  <Grid ColumnDefinitions="Auto,*">
-
-                    <!-- Check circle -->
-                    <Button Grid.Column="0"
-                            Classes="flat"
-                            Padding="0"
-                            Margin="0,0,8,0"
-                            VerticalAlignment="Center"
-                            Command="{Binding $parent[ItemsControl].((vm:DetailsIslandViewModel)DataContext).ToggleSubtaskDoneCommand}"
-                            CommandParameter="{Binding}">
-                      <Ellipse Classes="task-check"
-                               Classes.done="{Binding Done}"
-                               Width="16" Height="16"
-                               Cursor="Hand"/>
-                    </Button>
-
-                    <!-- Title / edit -->
-                    <Panel Grid.Column="1" VerticalAlignment="Center">
-                      <TextBlock Classes="subtask-title"
-                                 Text="{Binding Title}"
-                                 IsVisible="{Binding !IsEditing}"
+                      <!-- Title / edit -->
+                      <Panel Grid.Column="1" VerticalAlignment="Center">
+                        <TextBlock Classes="subtask-title"
+                                   Text="{Binding Title}"
+                                   IsVisible="{Binding !IsEditing}"
+                                   FontSize="{StaticResource FontSizeBody}"
+                                   Foreground="{DynamicResource TextDimBrush}"
+                                   VerticalAlignment="Center"
+                                   TextWrapping="Wrap"
+                                   Cursor="Ibeam"
+                                   Tapped="OnSubtaskTitleTapped"/>
+                        <TextBox Classes="subtask-edit"
+                                 Text="{Binding Title, Mode=TwoWay}"
+                                 IsVisible="{Binding IsEditing}"
                                  FontSize="{StaticResource FontSizeBody}"
-                                 Foreground="{DynamicResource TextDimBrush}"
-                                 VerticalAlignment="Center"
+                                 AcceptsReturn="False"
                                  TextWrapping="Wrap"
-                                 Cursor="Ibeam"
-                                 Tapped="OnSubtaskTitleTapped"/>
-                      <TextBox Classes="subtask-edit"
-                               Text="{Binding Title, Mode=TwoWay}"
-                               IsVisible="{Binding IsEditing}"
-                               FontSize="{StaticResource FontSizeBody}"
-                               AcceptsReturn="False"
-                               TextWrapping="Wrap"
-                               LostFocus="OnSubtaskEditLostFocus">
-                        <TextBox.KeyBindings>
-                          <KeyBinding Gesture="Enter"
-                                      Command="{Binding $parent[ItemsControl].((vm:DetailsIslandViewModel)DataContext).CommitSubtaskEditCommand}"
-                                      CommandParameter="{Binding}"/>
-                        </TextBox.KeyBindings>
-                      </TextBox>
-                    </Panel>
+                                 LostFocus="OnSubtaskEditLostFocus">
+                          <TextBox.KeyBindings>
+                            <KeyBinding Gesture="Enter"
+                                        Command="{Binding $parent[ItemsControl].((vm:DetailsIslandViewModel)DataContext).CommitSubtaskEditCommand}"
+                                        CommandParameter="{Binding}"/>
+                          </TextBox.KeyBindings>
+                        </TextBox>
+                      </Panel>
 
-                  </Grid>
-                </Border>
-              </DataTemplate>
-            </ItemsControl.ItemTemplate>
-              </ItemsControl>
-            </StackPanel>
+                    </Grid>
+                  </Border>
+                </DataTemplate>
+              </ItemsControl.ItemTemplate>
+            </ItemsControl>
           </StackPanel>
-        </Border>
-
-        <!-- Attachments section -->
-        <Border BorderBrush="{DynamicResource LineBrush}"
-                BorderThickness="0,1,0,0"
-                Padding="0,8,0,0">
-          <StackPanel Spacing="6">
-            <TextBlock Classes="section-label" Text="{loc:Tr details.attachments.sectionLabel}"/>
 
+          <!-- Files -->
+          <StackPanel IsVisible="{Binding IsFilesSection}" Spacing="6">
             <!-- Attachment rows -->
             <ItemsControl ItemsSource="{Binding Attachments}">
               <ItemsControl.ItemTemplate>
@@ -211,9 +234,8 @@
                        Foreground="{DynamicResource TextMuteBrush}"
                        TextWrapping="Wrap"/>
           </StackPanel>
-        </Border>
 
-      </StackPanel>
+        </Panel>
       </ScrollViewer>
     </DockPanel>
   </Border>