diff --git a/src/ClaudeDo.Ui/Views/Islands/DetailsIslandView.axaml b/src/ClaudeDo.Ui/Views/Islands/DetailsIslandView.axaml
index 4fb454f..35b3337 100644
--- a/src/ClaudeDo.Ui/Views/Islands/DetailsIslandView.axaml
+++ b/src/ClaudeDo.Ui/Views/Islands/DetailsIslandView.axaml
@@ -128,9 +128,7 @@
       <StackPanel Spacing="0">
 
         <!-- Planning merge section — visible only for planning parent tasks -->
-        <Border Padding="18,12,18,12"
-                BorderBrush="{DynamicResource LineBrush}"
-                BorderThickness="0,0,0,1"
+        <Border Classes="section-divider"
                 IsVisible="{Binding Task.IsPlanningParent}">
           <StackPanel Spacing="8">
             <TextBlock Classes="section-label" Text="MERGE" Margin="0,0,0,2"/>
@@ -156,9 +154,7 @@
         </Border>
 
         <!-- Steps section -->
-        <Border Padding="18,12,18,12"
-                BorderBrush="{DynamicResource LineBrush}"
-                BorderThickness="0,0,0,1">
+        <Border Classes="section-divider">
           <StackPanel Spacing="6">
             <TextBlock Classes="section-label" Text="STEPS" Margin="0,0,0,2"/>
             <TextBox Text="{Binding NewSubtaskTitle, Mode=TwoWay}"
@@ -206,9 +202,7 @@
         </Border>
 
         <!-- Details (description) section -->
-        <Border Padding="18,12,18,12"
-                BorderBrush="{DynamicResource LineBrush}"
-                BorderThickness="0,0,0,1">
+        <Border Classes="section-divider">
           <StackPanel Spacing="6">
             <Grid ColumnDefinitions="Auto,*,Auto,Auto">
               <Button Grid.Column="0"