diff --git a/frontend/src/pages/FlowPilotSessionPage.tsx b/frontend/src/pages/FlowPilotSessionPage.tsx
index 1e138719..db549cbd 100644
--- a/frontend/src/pages/FlowPilotSessionPage.tsx
+++ b/frontend/src/pages/FlowPilotSessionPage.tsx
@@ -139,9 +139,11 @@ export default function FlowPilotSessionPage() {
     )
   }
 
-  // Active/completed session
+  // Active/completed session — use calc(100vh-56px) to match tree editor pattern
+  // (56px = topbar height). This bypasses the flex height chain which doesn't
+  // reliably propagate through the grid → main → outlet → page chain.
   return (
-    <div className="flex h-full flex-col">
+    <div className="flex h-[calc(100vh-56px)] flex-col overflow-hidden">
       {/* Header */}
       <div
         className="flex items-center gap-3 border-b px-5 py-3 shrink-0"