diff --git a/src/ClaudeDo.App/App.axaml b/src/ClaudeDo.App/App.axaml
index e7e3f98..baedc85 100644
--- a/src/ClaudeDo.App/App.axaml
+++ b/src/ClaudeDo.App/App.axaml
@@ -31,6 +31,13 @@
     <Application.Styles>
         <FluentTheme />
         <StyleInclude Source="avares://ClaudeDo.Ui/Design/IslandStyles.axaml" />
+        <!-- Global defaults: every Window inherits Inter Tight + body size.
+             Controls that need mono opt in via their own class/style. -->
+        <Style Selector="Window">
+            <Setter Property="FontFamily" Value="{DynamicResource SansFont}" />
+            <Setter Property="FontSize" Value="{DynamicResource FontSizeBody}" />
+            <Setter Property="Foreground" Value="{DynamicResource TextBrush}" />
+        </Style>
         <Style Selector="ListBoxItem:selected /template/ ContentPresenter">
             <Setter Property="Background" Value="{DynamicResource AccentGlowBrush}"/>
         </Style>