diff --git a/frontend/src/components/common/Modal.tsx b/frontend/src/components/common/Modal.tsx
index 73cf54ad..f798e4bb 100644
--- a/frontend/src/components/common/Modal.tsx
+++ b/frontend/src/components/common/Modal.tsx
@@ -1,5 +1,5 @@
-import { useEffect, useCallback, type ReactNode } from 'react'
-import { X } from 'lucide-react'
+import { useState, useEffect, useCallback, type ReactNode } from 'react'
+import { X, Maximize2, Minimize2 } from 'lucide-react'
 import { cn } from '@/lib/utils'
 
 interface ModalProps {
@@ -10,9 +10,28 @@ interface ModalProps {
   /** Optional footer content that stays fixed at bottom (doesn't scroll) */
   footer?: ReactNode
   size?: 'sm' | 'md' | 'lg' | 'xl'
+  /** If true, a fullscreen toggle button appears in the modal header */
+  allowFullScreen?: boolean
 }
 
-export function Modal({ isOpen, onClose, title, children, footer, size = 'md' }: ModalProps) {
+export function Modal({ isOpen, onClose, title, children, footer, size = 'md', allowFullScreen = false }: ModalProps) {
+  const [isFullScreen, setIsFullScreen] = useState(() => {
+    if (!allowFullScreen) return false
+    try {
+      return localStorage.getItem('rf-editor-fullscreen') === 'true'
+    } catch {
+      return false
+    }
+  })
+
+  const toggleFullScreen = () => {
+    const next = !isFullScreen
+    setIsFullScreen(next)
+    try {
+      localStorage.setItem('rf-editor-fullscreen', String(next))
+    } catch {}
+  }
+
   // Close on Escape key
   const handleKeyDown = useCallback(
     (e: KeyboardEvent) => {
@@ -61,9 +80,13 @@ export function Modal({ isOpen, onClose, title, children, footer, size = 'md' }:
       <div
         className={cn(
           'relative flex w-full flex-col border border-border bg-card shadow-lg',
-          'max-h-[100vh] rounded-t-2xl sm:max-h-[85vh] sm:rounded-2xl',
-          'animate-scale-in',
-          sizeClasses[size]
+          'animate-scale-in transition-all duration-200',
+          isFullScreen
+            ? 'fixed inset-4 max-w-none w-auto h-auto rounded-2xl'
+            : cn(
+                'max-h-[100vh] rounded-t-2xl sm:max-h-[85vh] sm:rounded-2xl',
+                sizeClasses[size]
+              )
         )}
       >
         {/* Header - Fixed at top */}
@@ -71,17 +94,32 @@ export function Modal({ isOpen, onClose, title, children, footer, size = 'md' }:
           <h2 id="modal-title" className="text-lg font-semibold text-foreground">
             {title}
           </h2>
-          <button
-            onClick={onClose}
-            className={cn(
-              'rounded-md p-1.5 text-muted-foreground transition-colors sm:p-1',
-              'hover:bg-accent hover:text-foreground',
-              'focus:outline-none focus:ring-2 focus:ring-primary/20'
+          <div className="flex items-center gap-1">
+            {allowFullScreen && (
+              <button
+                type="button"
+                onClick={toggleFullScreen}
+                className="rounded-md p-1 text-muted-foreground hover:bg-accent hover:text-foreground"
+                title={isFullScreen ? 'Exit full screen' : 'Full screen'}
+              >
+                {isFullScreen
+                  ? <Minimize2 className="h-4 w-4" />
+                  : <Maximize2 className="h-4 w-4" />
+                }
+              </button>
             )}
-            aria-label="Close modal"
-          >
-            <X className="h-5 w-5" />
-          </button>
+            <button
+              onClick={onClose}
+              className={cn(
+                'rounded-md p-1.5 text-muted-foreground transition-colors sm:p-1',
+                'hover:bg-accent hover:text-foreground',
+                'focus:outline-none focus:ring-2 focus:ring-primary/20'
+              )}
+              aria-label="Close modal"
+            >
+              <X className="h-5 w-5" />
+            </button>
+          </div>
         </div>
 
         {/* Body - Scrollable */}
diff --git a/frontend/src/components/tree-editor/NodeEditorModal.tsx b/frontend/src/components/tree-editor/NodeEditorModal.tsx
index 95f55ef5..96fbc31e 100644
--- a/frontend/src/components/tree-editor/NodeEditorModal.tsx
+++ b/frontend/src/components/tree-editor/NodeEditorModal.tsx
@@ -83,7 +83,7 @@ export function NodeEditorModal({ node, onClose, isNewNode = false }: NodeEditor
   )
 
   return (
-    <Modal isOpen={true} onClose={onClose} title={getTitle()} size="lg" footer={footerContent}>
+    <Modal isOpen={true} onClose={onClose} title={getTitle()} size="lg" footer={footerContent} allowFullScreen={true}>
       {/* Node ID display */}
       <div className="mb-4 text-xs text-muted-foreground">
         Node ID: <code className="rounded bg-accent px-1 py-0.5">{node.id}</code>