diff --git a/src/Junction.App/Views/MachineConfigView.axaml b/src/Junction.App/Views/MachineConfigView.axaml
index 5ccee4c..0100cbd 100644
--- a/src/Junction.App/Views/MachineConfigView.axaml
+++ b/src/Junction.App/Views/MachineConfigView.axaml
@@ -8,120 +8,128 @@
              x:DataType="vm:MachineConfigViewModel"
              x:CompileBindings="True">
 
-  <DockPanel Margin="20">
+  <!-- header / body / footer -->
+  <Grid Margin="20" RowDefinitions="Auto,*,Auto">
 
     <!-- Header -->
-    <TextBlock DockPanel.Dock="Top" Classes="h1"
+    <TextBlock Grid.Row="0" Classes="h1"
                Text="{Binding Title}"
                Margin="0,0,0,16" />
 
-    <!-- Action bar -->
-    <StackPanel DockPanel.Dock="Bottom" Orientation="Horizontal" Spacing="12" Margin="0,16,0,0">
-      <Button Classes="accent" Content="Save" Command="{Binding SaveCommand}" IsDefault="True" />
-      <Button Content="Cancel" Command="{Binding CancelCommand}" />
+    <!-- Body: fixed form column + stretching data-items column -->
+    <Grid Grid.Row="1" ColumnDefinitions="Auto,*">
+
+      <!-- Form -->
+      <Border Grid.Column="0" Classes="card" Width="380" VerticalAlignment="Top">
+        <StackPanel Spacing="12">
+
+          <StackPanel Spacing="4">
+            <TextBlock Classes="fieldLabel" Text="Name" />
+            <TextBox Text="{Binding Name}" Watermark="Machine name" />
+          </StackPanel>
+
+          <StackPanel Spacing="4">
+            <TextBlock Classes="fieldLabel" Text="Protocol" />
+            <ComboBox ItemsSource="{Binding AvailableProtocols}"
+                      SelectedItem="{Binding SelectedProtocol}"
+                      HorizontalAlignment="Stretch"
+                      PlaceholderText="Select a protocol" />
+          </StackPanel>
+
+          <StackPanel Spacing="4">
+            <TextBlock Classes="fieldLabel" Text="Agent URL" />
+            <TextBox Text="{Binding AgentUrl}" Watermark="http://host:5000" />
+          </StackPanel>
+
+          <StackPanel Spacing="4">
+            <TextBlock Classes="fieldLabel" Text="Poll Interval (seconds)" />
+            <TextBox Text="{Binding PollIntervalSeconds}" Width="120" HorizontalAlignment="Left" />
+          </StackPanel>
+
+        </StackPanel>
+      </Border>
+
+      <!-- Data items to monitor (fills remaining width + height) -->
+      <Border Grid.Column="1" Classes="card" Margin="16,0,0,0" HorizontalAlignment="Stretch">
+        <DockPanel>
+
+          <TextBlock DockPanel.Dock="Top" Classes="h2" Text="Data items to monitor"
+                     Margin="0,0,0,8" />
+
+          <!-- Controls row -->
+          <StackPanel DockPanel.Dock="Top" Orientation="Horizontal" Spacing="8" Margin="0,0,0,8">
+            <Button Content="Load available items"
+                    Command="{Binding LoadItemsCommand}" />
+            <Button Content="Select all"
+                    Command="{Binding SelectAllCommand}" />
+            <Button Content="Select none"
+                    Command="{Binding SelectNoneCommand}" />
+            <ProgressBar IsIndeterminate="True"
+                         IsVisible="{Binding IsProbing}"
+                         Width="120" VerticalAlignment="Center" />
+          </StackPanel>
+
+          <!-- Status message -->
+          <TextBlock DockPanel.Dock="Top" Classes="subtle"
+                     Text="{Binding ItemsStatus}"
+                     IsVisible="{Binding HasItemsStatus}"
+                     TextWrapping="Wrap" Margin="0,0,0,8" />
+
+          <!-- Column header -->
+          <Border DockPanel.Dock="Top"
+                  BorderThickness="0,0,0,1"
+                  BorderBrush="{DynamicResource CardBorderBrush}"
+                  Padding="0,0,0,4" Margin="0,0,0,4">
+            <Grid ColumnDefinitions="Auto,2*,1.2*,1.2*,1*" Margin="0,0,8,0">
+              <TextBlock Grid.Column="0" Text="" Width="28" />
+              <TextBlock Grid.Column="1" Classes="fieldLabel" Text="Name" />
+              <TextBlock Grid.Column="2" Classes="fieldLabel" Text="Type" />
+              <TextBlock Grid.Column="3" Classes="fieldLabel" Text="Category" />
+              <TextBlock Grid.Column="4" Classes="fieldLabel" Text="Units" />
+            </Grid>
+          </Border>
+
+          <!-- Scrollable checklist (fills remaining height) -->
+          <ScrollViewer>
+            <ItemsControl ItemsSource="{Binding AvailableItems}">
+              <ItemsControl.ItemTemplate>
+                <DataTemplate x:DataType="vm:SelectableDataItemViewModel">
+                  <Grid ColumnDefinitions="Auto,2*,1.2*,1.2*,1*" Margin="0,3">
+                    <CheckBox Grid.Column="0" Width="28"
+                              IsChecked="{Binding IsSelected}"
+                              VerticalAlignment="Center" />
+                    <StackPanel Grid.Column="1" VerticalAlignment="Center">
+                      <TextBlock Text="{Binding Name}" FontWeight="SemiBold" TextWrapping="Wrap" />
+                      <TextBlock Text="{Binding Id}" Classes="subtle" FontSize="11" TextWrapping="Wrap" />
+                    </StackPanel>
+                    <TextBlock Grid.Column="2" Text="{Binding Type}" VerticalAlignment="Center" TextWrapping="Wrap" />
+                    <TextBlock Grid.Column="3" Text="{Binding Category}" VerticalAlignment="Center" TextWrapping="Wrap" />
+                    <TextBlock Grid.Column="4" Text="{Binding Units}" VerticalAlignment="Center" TextWrapping="Wrap" />
+                  </Grid>
+                </DataTemplate>
+              </ItemsControl.ItemTemplate>
+            </ItemsControl>
+          </ScrollViewer>
+
+        </DockPanel>
+      </Border>
+    </Grid>
+
+    <!-- Footer: validation hint + action bar, full width -->
+    <StackPanel Grid.Row="2" Spacing="0">
+      <!-- Inline validation hint -->
+      <TextBlock Text="{Binding ValidationError}"
+                 IsVisible="{Binding HasValidationError}"
+                 Foreground="{DynamicResource DangerBrush}"
+                 TextWrapping="Wrap"
+                 Margin="0,12,0,0" />
+
+      <!-- Action bar -->
+      <StackPanel Orientation="Horizontal" Spacing="12" Margin="0,16,0,0">
+        <Button Classes="accent" Content="Save" Command="{Binding SaveCommand}" IsDefault="True" />
+        <Button Content="Cancel" Command="{Binding CancelCommand}" />
+      </StackPanel>
     </StackPanel>
 
-    <!-- Inline validation hint -->
-    <TextBlock DockPanel.Dock="Bottom"
-               Text="{Binding ValidationError}"
-               IsVisible="{Binding HasValidationError}"
-               Foreground="{DynamicResource DangerBrush}"
-               TextWrapping="Wrap"
-               Margin="0,12,0,0" />
-
-    <!-- Form -->
-    <Border DockPanel.Dock="Top" Classes="card" MaxWidth="480" HorizontalAlignment="Left">
-      <StackPanel Spacing="12">
-
-        <StackPanel Spacing="4">
-          <TextBlock Classes="fieldLabel" Text="Name" />
-          <TextBox Text="{Binding Name}" Watermark="Machine name" />
-        </StackPanel>
-
-        <StackPanel Spacing="4">
-          <TextBlock Classes="fieldLabel" Text="Protocol" />
-          <ComboBox ItemsSource="{Binding AvailableProtocols}"
-                    SelectedItem="{Binding SelectedProtocol}"
-                    HorizontalAlignment="Stretch"
-                    PlaceholderText="Select a protocol" />
-        </StackPanel>
-
-        <StackPanel Spacing="4">
-          <TextBlock Classes="fieldLabel" Text="Agent URL" />
-          <TextBox Text="{Binding AgentUrl}" Watermark="http://host:5000" />
-        </StackPanel>
-
-        <StackPanel Spacing="4">
-          <TextBlock Classes="fieldLabel" Text="Poll Interval (seconds)" />
-          <TextBox Text="{Binding PollIntervalSeconds}" Width="120" HorizontalAlignment="Left" />
-        </StackPanel>
-
-      </StackPanel>
-    </Border>
-
-    <!-- Data items to monitor (fills remaining space) -->
-    <Border Classes="card" Margin="0,16,0,0" MaxWidth="640" HorizontalAlignment="Left">
-      <DockPanel>
-
-        <TextBlock DockPanel.Dock="Top" Classes="h2" Text="Data items to monitor"
-                   Margin="0,0,0,8" />
-
-        <!-- Controls row -->
-        <StackPanel DockPanel.Dock="Top" Orientation="Horizontal" Spacing="8" Margin="0,0,0,8">
-          <Button Content="Load available items"
-                  Command="{Binding LoadItemsCommand}" />
-          <Button Content="Select all"
-                  Command="{Binding SelectAllCommand}" />
-          <Button Content="Select none"
-                  Command="{Binding SelectNoneCommand}" />
-          <ProgressBar IsIndeterminate="True"
-                       IsVisible="{Binding IsProbing}"
-                       Width="120" VerticalAlignment="Center" />
-        </StackPanel>
-
-        <!-- Status message -->
-        <TextBlock DockPanel.Dock="Top" Classes="subtle"
-                   Text="{Binding ItemsStatus}"
-                   IsVisible="{Binding HasItemsStatus}"
-                   TextWrapping="Wrap" Margin="0,0,0,8" />
-
-        <!-- Column header -->
-        <Border DockPanel.Dock="Top"
-                BorderThickness="0,0,0,1"
-                BorderBrush="{DynamicResource CardBorderBrush}"
-                Padding="0,0,0,4" Margin="0,0,0,4">
-          <Grid ColumnDefinitions="Auto,2*,1.2*,1.2*,1*" Margin="0,0,8,0">
-            <TextBlock Grid.Column="0" Text="" Width="28" />
-            <TextBlock Grid.Column="1" Classes="fieldLabel" Text="Name" />
-            <TextBlock Grid.Column="2" Classes="fieldLabel" Text="Type" />
-            <TextBlock Grid.Column="3" Classes="fieldLabel" Text="Category" />
-            <TextBlock Grid.Column="4" Classes="fieldLabel" Text="Units" />
-          </Grid>
-        </Border>
-
-        <!-- Scrollable checklist -->
-        <ScrollViewer MaxHeight="320">
-          <ItemsControl ItemsSource="{Binding AvailableItems}">
-            <ItemsControl.ItemTemplate>
-              <DataTemplate x:DataType="vm:SelectableDataItemViewModel">
-                <Grid ColumnDefinitions="Auto,2*,1.2*,1.2*,1*" Margin="0,3">
-                  <CheckBox Grid.Column="0" Width="28"
-                            IsChecked="{Binding IsSelected}"
-                            VerticalAlignment="Center" />
-                  <StackPanel Grid.Column="1" VerticalAlignment="Center">
-                    <TextBlock Text="{Binding Name}" FontWeight="SemiBold" TextWrapping="Wrap" />
-                    <TextBlock Text="{Binding Id}" Classes="subtle" FontSize="11" TextWrapping="Wrap" />
-                  </StackPanel>
-                  <TextBlock Grid.Column="2" Text="{Binding Type}" VerticalAlignment="Center" TextWrapping="Wrap" />
-                  <TextBlock Grid.Column="3" Text="{Binding Category}" VerticalAlignment="Center" TextWrapping="Wrap" />
-                  <TextBlock Grid.Column="4" Text="{Binding Units}" VerticalAlignment="Center" TextWrapping="Wrap" />
-                </Grid>
-              </DataTemplate>
-            </ItemsControl.ItemTemplate>
-          </ItemsControl>
-        </ScrollViewer>
-
-      </DockPanel>
-    </Border>
-  </DockPanel>
+  </Grid>
 </UserControl>