diff --git a/src/runtime/endor_host/tests.rs b/src/runtime/endor_host/tests.rs
index fbd93c4..52d41b7 100644
--- a/src/runtime/endor_host/tests.rs
+++ b/src/runtime/endor_host/tests.rs
@@ -207,8 +207,10 @@ page.render(Column(0,8,Column(0,8,paragraph,tail),Column(50,8,paragraph)))
             })
             .collect();
         assert_eq!(commands.len(), 2);
-        assert_eq!(commands[0][0], 240.0);
-        assert_eq!(commands[1][0], 140.0);
+        // The 240px window reserves 56px for the rail and 8px for its inset.
+        // The second occurrence additionally has 50px padding on each side.
+        assert_eq!(commands[0][0], 176.0);
+        assert_eq!(commands[1][0], 76.0);
         assert!(commands[1][1] > commands[0][1]);
         let tail = initial
             .frame
@@ -236,6 +238,20 @@ page.render(Column(0,8,Column(0,8,paragraph,tail),Column(50,8,paragraph)))
                 .map(|m| m.id)
                 .collect::<Vec<_>>()
         );
+        let widths: Vec<_> = resized
+            .frame
+            .commands
+            .iter()
+            .filter_map(|command| match command {
+                RenderCommand::Text {
+                    value,
+                    wrap_bounds: Some(bounds),
+                    ..
+                } if value == &text => Some(bounds[0]),
+                _ => None,
+            })
+            .collect();
+        assert_eq!(widths, [336.0, 236.0]);
         let heights: Vec<_> = resized
             .frame
             .commands
@@ -1758,6 +1774,15 @@ fn viewport_resize_changes_constraints_and_preserves_mount_identity_without_sour
         }),
     )
     .unwrap();
+    // Page content excludes the 56px rail, 8px inset and 24px root padding
+    // on each side, both initially and after resizing the outer window.
+    assert!(
+        initial
+            .frame
+            .mounts
+            .iter()
+            .any(|mount| mount.width == 688.0 && mount.height == 24.0)
+    );
     let ids: Vec<_> = initial.frame.mounts.iter().map(|mount| mount.id).collect();
     let document = session
         .resize(Some(crate::layout::Size {
@@ -1780,7 +1805,7 @@ fn viewport_resize_changes_constraints_and_preserves_mount_identity_without_sour
             .frame
             .mounts
             .iter()
-            .any(|mount| mount.width == 312.0 && mount.height == 24.0)
+            .any(|mount| mount.width == 248.0 && mount.height == 24.0)
     );
     assert_eq!(session.inputs, 0);
     assert!(