diff --git a/apps/ai-game-creator-shell/src/features/ui-editor/treeUtils.ts b/apps/ai-game-creator-shell/src/features/ui-editor/treeUtils.ts
new file mode 100644
index 000000000..9e044efb8
--- /dev/null
+++ b/apps/ai-game-creator-shell/src/features/ui-editor/treeUtils.ts
@@ -0,0 +1,16 @@
+import type { Node as UiNode } from './types/Node';
+import type { NodeId } from './types/NodeId';
+
+export function visitUiNodes(
+  root: UiNode,
+  visit: (node: UiNode) => void,
+): void {
+  visit(root);
+  for (const child of root.children) visitUiNodes(child, visit);
+}
+
+export function collectUiNodeIds(root: UiNode): Set<NodeId> {
+  const ids = new Set<NodeId>();
+  visitUiNodes(root, (node) => ids.add(node.id));
+  return ids;
+}
diff --git a/apps/ai-game-creator-shell/src/features/ui-editor/types/UiNodeMoveRequest.ts b/apps/ai-game-creator-shell/src/features/ui-editor/types/UiNodeMoveRequest.ts
new file mode 100644
index 000000000..11d021c1c
--- /dev/null
+++ b/apps/ai-game-creator-shell/src/features/ui-editor/types/UiNodeMoveRequest.ts
@@ -0,0 +1,11 @@
+import type { NodeId } from './NodeId';
+import type { UIDesignImageId } from './UIDesignImageId';
+
+/** UI 节点移动的完整上下文，避免在树视图与状态层之间散落五个并行参数。 */
+export type UiNodeMoveRequest = {
+  sourceTreeId: UIDesignImageId;
+  targetTreeId: UIDesignImageId;
+  nodeId: NodeId;
+  targetParentId: NodeId;
+  targetIndex: number;
+};
diff --git a/apps/ai-game-creator-shell/src/features/ui-editor/useUiEditorState.ts b/apps/ai-game-creator-shell/src/features/ui-editor/useUiEditorState.ts
index 95f585a63..bf81a6fc0 100644
--- a/apps/ai-game-creator-shell/src/features/ui-editor/useUiEditorState.ts
+++ b/apps/ai-game-creator-shell/src/features/ui-editor/useUiEditorState.ts
@@ -14,6 +14,7 @@ import type { State } from './types/State';
 import type { UIDesignImage } from './types/UIDesignImage';
 import type { UIDesignImageId } from './types/UIDesignImageId';
 import type { UIDesignImageRole } from './types/UIDesignImageRole';
+import type { UiNodeMoveRequest } from './types/UiNodeMoveRequest';
 
 export const EMPTY_UI_EDITOR_STATE: State = {
   ui_trees: [],
@@ -1151,13 +1152,13 @@ export function useUiEditorState(initialState: State = EMPTY_UI_EDITOR_STATE) {
   );
 
   const moveNode = useCallback(
-    (
-      sourceTreeId: UIDesignImageId,
-      targetTreeId: UIDesignImageId,
-      nodeId: NodeId,
-      targetParentId: NodeId,
-      targetIndex: number,
-    ): UiEditorOperationResult => {
+    ({
+      sourceTreeId,
+      targetTreeId,
+      nodeId,
+      targetParentId,
+      targetIndex,
+    }: UiNodeMoveRequest): UiEditorOperationResult => {
       const blocked = guard();
       if (blocked) return blocked;
       if (!Number.isInteger(targetIndex) || targetIndex < 0) {
@@ -1189,6 +1190,44 @@ export function useUiEditorState(initialState: State = EMPTY_UI_EDITOR_STATE) {
       ) {
         return { ok: false, reason: 'invalid' };
       }
+      let nextTransform: Node['transform'] | null = null;
+      if (sourceTreeId === targetTreeId) {
+        const image = current.ui_design_images[sourceTreeId];
+        if (!image) return { ok: false, reason: 'missing' };
+        const logicalSize: Rect = {
+          min: [0, 0],
+          size: [
+            image.pixel_size[0] / image.pixels_per_unit,
+            image.pixel_size[1] / image.pixels_per_unit,
+          ],
+        };
+        if (
+          !isValidRect(logicalSize) ||
+          logicalSize.size.some((value) => value <= 0)
+        ) {
+          return { ok: false, reason: 'invalid' };
+        }
+        const pageRect = findNodePageRect(sourceTree.root, nodeId, logicalSize);
+        const targetPageRect = findNodePageRect(
+          targetTree.root,
+          targetParentId,
+          logicalSize,
+        );
+        if (
+          !pageRect ||
+          pageRect.size.some((value) => value <= 0) ||
+          !targetPageRect ||
+          targetPageRect.size.some((value) => value <= 0)
+        ) {
+          return { ok: false, reason: 'invalid' };
+        }
+        nextTransform = setOffsetsForPageRect(
+          source.node.transform,
+          pageRect,
+          targetPageRect,
+        );
+        if (!nextTransform) return { ok: false, reason: 'invalid' };
+      }
       const next = cloneState(current);
       const nextSourceTree = next.ui_trees.find(
         (candidate) => candidate.src_ui_design === sourceTreeId,
@@ -1208,8 +1247,9 @@ export function useUiEditorState(initialState: State = EMPTY_UI_EDITOR_STATE) {
         ? nextSource.parent.children.splice(nextSource.index, 1)
         : [];
       if (!moved) return { ok: false, reason: 'invalid' };
-      // TODO: Cross-tree moves intentionally preserve the local transform.
-      // Coordinate conversion between design images can be added separately.
+      // 跨树时只保留节点原本的局部 transform；源、目标界面图的画布和父级坐标空间独立，
+      // “保留 transform”不等于承诺页面位置稳定。只有同树移动才在上面做页面矩形换算。
+      if (nextTransform) moved.transform = nextTransform;
       nextTarget.children.splice(targetIndex, 0, moved);
       commit(next);
       return { ok: true, value: undefined };
diff --git a/apps/ai-game-creator-shell/src/view/ui-editor/components/InputSidebar.tsx b/apps/ai-game-creator-shell/src/view/ui-editor/components/InputSidebar.tsx
index 424aedbde..49d76bfb4 100644
--- a/apps/ai-game-creator-shell/src/view/ui-editor/components/InputSidebar.tsx
+++ b/apps/ai-game-creator-shell/src/view/ui-editor/components/InputSidebar.tsx
@@ -1,6 +1,7 @@
 import { Image as ImageIcon, Plus, ScanSearch, Type } from 'lucide-react';
 import { useMemo } from 'react';
 
+import { visitUiNodes } from '../../../features/ui-editor/treeUtils';
 import type { Node as UiNode } from '../../../features/ui-editor/types/Node';
 import type { NodeId } from '../../../features/ui-editor/types/NodeId';
 import type { UIDesignImageId } from '../../../features/ui-editor/types/UIDesignImageId';
@@ -10,15 +11,6 @@ import { UiTreePanel } from './UiTreePanel';
 
 const SUPER_ROOT_ID = '__ui-editor-super-root__';
 
-function visitTreeNodes(
-  node: UiNode,
-  treeId: UIDesignImageId,
-  result: Map<NodeId, UIDesignImageId>,
-) {
-  result.set(node.id, treeId);
-  for (const child of node.children) visitTreeNodes(child, treeId, result);
-}
-
 export function InputSidebar({
   controller,
 }: {
@@ -44,21 +36,13 @@ export function InputSidebar({
   const treeIdByNodeId = useMemo(() => {
     const result = new Map<NodeId, UIDesignImageId>();
     for (const tree of editor.state.ui_trees) {
-      visitTreeNodes(tree.root, tree.src_ui_design, result);
+      visitUiNodes(tree.root, (node) =>
+        result.set(node.id, tree.src_ui_design),
+      );
     }
     return result;
   }, [editor.state.ui_trees]);
 
-  const hiddenNodeIdsByTree = useMemo(() => {
-    const result = new Map<UIDesignImageId, ReadonlySet<NodeId>>();
-    for (const [treeId, hiddenNodeIds] of Object.entries(
-      controller.hiddenNodeIdsByImage,
-    )) {
-      result.set(treeId, new Set(Object.keys(hiddenNodeIds)));
-    }
-    return result;
-  }, [controller.hiddenNodeIdsByImage]);
-
   const superRoot = useMemo<UiNode | null>(() => {
     if (editor.state.ui_trees.length === 0) return null;
     return {
@@ -330,15 +314,13 @@ export function InputSidebar({
         selectedNodeId={selectedNodeId}
         focusRequest={focusRequest}
         treeIdForNode={(nodeId) => treeIdByNodeId.get(nodeId) ?? null}
-        hiddenNodeIdsForTree={(treeId) =>
-          hiddenNodeIdsByTree.get(treeId) ?? new Set<NodeId>()
-        }
+        hiddenNodeIds={controller.hiddenNodeIds}
         onSelectNode={(treeId, nodeId) => {
           controller.selectDesignImage(treeId);
           controller.selectNode(nodeId);
         }}
-        onToggleNodeVisibility={(treeId, nodeId) =>
-          controller.toggleNodePreviewVisibility(nodeId, treeId)
+        onToggleNodeVisibility={(nodeId) =>
+          controller.toggleNodePreviewVisibility(nodeId)
         }
         onInsertNode={(treeId, parentId) => {
           controller.insertNode(parentId, treeId);
@@ -349,21 +331,7 @@ export function InputSidebar({
         onDeleteNode={(treeId, nodeId) => {
           controller.deleteNode(nodeId, treeId);
         }}
-        onMoveNode={(
-          sourceTreeId,
-          targetTreeId,
-          nodeId,
-          targetParentId,
-          targetIndex,
-        ) => {
-          controller.moveNode(
-            sourceTreeId,
-            targetTreeId,
-            nodeId,
-            targetParentId,
-            targetIndex,
-          );
-        }}
+        onMoveNode={(request) => controller.moveNode(request)}
       />
     </aside>
   );
diff --git a/apps/ai-game-creator-shell/src/view/ui-editor/components/UiTreePanel.tsx b/apps/ai-game-creator-shell/src/view/ui-editor/components/UiTreePanel.tsx
index a99396730..901983ec9 100644
--- a/apps/ai-game-creator-shell/src/view/ui-editor/components/UiTreePanel.tsx
+++ b/apps/ai-game-creator-shell/src/view/ui-editor/components/UiTreePanel.tsx
@@ -16,28 +16,21 @@ import {
 import type { Node as UiNode } from '../../../features/ui-editor/types/Node';
 import type { NodeId } from '../../../features/ui-editor/types/NodeId';
 import type { UIDesignImageId } from '../../../features/ui-editor/types/UIDesignImageId';
+import type { UiNodeMoveRequest } from '../../../features/ui-editor/types/UiNodeMoveRequest';
 import type { UiEditorNodeFocusRequest } from '../model';
 
-const EMPTY_HIDDEN_NODE_IDS = new Set<NodeId>();
-
 type UiTreePanelProps = {
   root: UiNode | null;
   selectedNodeId: NodeId | null;
   focusRequest: UiEditorNodeFocusRequest | null;
   treeIdForNode: (nodeId: NodeId) => UIDesignImageId | null;
-  hiddenNodeIdsForTree: (treeId: UIDesignImageId) => ReadonlySet<NodeId>;
+  hiddenNodeIds: ReadonlySet<NodeId>;
   onSelectNode: (treeId: UIDesignImageId, id: NodeId) => void;
-  onToggleNodeVisibility: (treeId: UIDesignImageId, id: NodeId) => void;
+  onToggleNodeVisibility: (id: NodeId) => void;
   onInsertNode: (treeId: UIDesignImageId, parentId: NodeId) => void;
   onInsertNodeAfter: (treeId: UIDesignImageId, nodeId: NodeId) => void;
   onDeleteNode: (treeId: UIDesignImageId, nodeId: NodeId) => void;
-  onMoveNode: (
-    sourceTreeId: UIDesignImageId,
-    targetTreeId: UIDesignImageId,
-    nodeId: NodeId,
-    targetParentId: NodeId,
-    targetIndex: number,
-  ) => void;
+  onMoveNode: (request: UiNodeMoveRequest) => void;
 };
 
 function TreeRow({
@@ -118,7 +111,7 @@ export function UiTreePanel({
   selectedNodeId,
   focusRequest,
   treeIdForNode,
-  hiddenNodeIdsForTree,
+  hiddenNodeIds,
   onSelectNode,
   onToggleNodeVisibility,
   onInsertNode,
@@ -171,7 +164,13 @@ export function UiTreePanel({
       dragIds,
       siblingIds: destinationIds,
     });
-    onMoveNode(sourceTreeId, targetTreeId, nodeId, parentId, targetIndex);
+    onMoveNode({
+      sourceTreeId,
+      targetTreeId,
+      nodeId,
+      targetParentId: parentId,
+      targetIndex,
+    });
   };
 
   const pageRootIds = new Set(root?.children.map((child) => child.id) ?? []);
@@ -212,7 +211,6 @@ export function UiTreePanel({
             aria-label="UI 节点树"
           >
             {(props) => {
-              const treeId = treeIdForNode(props.node.data.id);
               return (
                 <TreeRow
                   {...props}
@@ -220,15 +218,8 @@ export function UiTreePanel({
                     const nodeTreeId = treeIdForNode(nodeId);
                     if (nodeTreeId) onSelectNode(nodeTreeId, nodeId);
                   }}
-                  hiddenNodeIds={
-                    treeId
-                      ? hiddenNodeIdsForTree(treeId)
-                      : EMPTY_HIDDEN_NODE_IDS
-                  }
-                  onToggleNodeVisibility={(nodeId) => {
-                    const nodeTreeId = treeIdForNode(nodeId);
-                    if (nodeTreeId) onToggleNodeVisibility(nodeTreeId, nodeId);
-                  }}
+                  hiddenNodeIds={hiddenNodeIds}
+                  onToggleNodeVisibility={onToggleNodeVisibility}
                   onOpenContextMenu={(event, nodeId) =>
                     nodeId === root.id
                       ? undefined
diff --git a/apps/ai-game-creator-shell/src/view/ui-editor/useUiEditorPage.ts b/apps/ai-game-creator-shell/src/view/ui-editor/useUiEditorPage.ts
index a371e5cb5..d3d6bea75 100644
--- a/apps/ai-game-creator-shell/src/view/ui-editor/useUiEditorPage.ts
+++ b/apps/ai-game-creator-shell/src/view/ui-editor/useUiEditorPage.ts
@@ -19,6 +19,7 @@ import {
   validateVisualBindingResult,
 } from '../../features/ui-editor/prerequisites';
 import { applyRecognitionResult } from '../../features/ui-editor/recognition';
+import { collectUiNodeIds } from '../../features/ui-editor/treeUtils';
 import type { BindingDTO } from '../../features/ui-editor/types/BindingDTO';
 import type { Component } from '../../features/ui-editor/types/Component';
 import type { FontAssetId } from '../../features/ui-editor/types/FontAssetId';
@@ -31,6 +32,7 @@ import type { SpriteBorder } from '../../features/ui-editor/types/SpriteBorder';
 import type { UIDesignImageId } from '../../features/ui-editor/types/UIDesignImageId';
 import type { UIDesignImageRole } from '../../features/ui-editor/types/UIDesignImageRole';
 import type { UIDesignSuggestionTreeNode } from '../../features/ui-editor/types/UIDesignSuggestionTreeNode';
+import type { UiNodeMoveRequest } from '../../features/ui-editor/types/UiNodeMoveRequest';
 import {
   mockUiDesignStateStore,
   type UiDesignStateStore,
@@ -58,18 +60,6 @@ import { useUiEditorNodeFocus } from './useUiEditorNodeFocus';
 
 const ASSET_BATCH_SIZE = 5;
 
-type HiddenNodeIdsByImage = Record<UIDesignImageId, Record<NodeId, true>>;
-
-function collectNodeIds(root: UiNode): Set<NodeId> {
-  const ids = new Set<NodeId>();
-  const visit = (node: UiNode) => {
-    ids.add(node.id);
-    for (const child of node.children) visit(child);
-  };
-  visit(root);
-  return ids;
-}
-
 export type PendingWorkflowStepChange = {
   from: UiEditorStepId;
   to: UiEditorStepId;
@@ -102,8 +92,10 @@ export function useUiEditorPage(
     null,
   );
   const [selectedNodeId, setSelectedNodeId] = useState<NodeId | null>(null);
-  const [hiddenNodeIdsByImage, setHiddenNodeIdsByImage] =
-    useState<HiddenNodeIdsByImage>({});
+  // NodeId 在 State 内全局唯一；隐藏状态直接记录节点 ID，跨树移动时随节点保留。
+  const [hiddenNodeIds, setHiddenNodeIds] = useState<Set<NodeId>>(
+    () => new Set(),
+  );
   const { focusRequest, focusNode } = useUiEditorNodeFocus({
     activateImage: setActiveImageId,
     clearSpriteSelection: () => setSelectedSpriteId(null),
@@ -137,7 +129,7 @@ export function useUiEditorPage(
       setIsLoading(false);
       setLoadError(null);
       setPersistedRevision(0);
-      setHiddenNodeIdsByImage({});
+      setHiddenNodeIds(new Set());
       return;
     }
     let cancelled = false;
@@ -156,7 +148,7 @@ export function useUiEditorPage(
           setActiveImageId(ids[0] ?? null);
           setSelectedNodeId(null);
           setSelectedSpriteId(null);
-          setHiddenNodeIdsByImage({});
+          setHiddenNodeIds(new Set());
           setPreviewUrls({});
           setPersistedRevision(revision);
           if (projectPath) {
@@ -277,83 +269,44 @@ export function useUiEditorPage(
     : null;
 
   useEffect(() => {
-    setHiddenNodeIdsByImage((current) => {
-      let changed = false;
-      const next: HiddenNodeIdsByImage = {};
-      for (const [treeId, hiddenNodeIds] of Object.entries(current)) {
-        const tree = editor.state.ui_trees.find(
-          (candidate) => candidate.src_ui_design === treeId,
-        );
-        if (!tree) {
-          changed = true;
-          continue;
-        }
-        const validNodeIds = collectNodeIds(tree.root);
-        const filtered = Object.fromEntries(
-          Object.keys(hiddenNodeIds)
-            .filter((nodeId) => validNodeIds.has(nodeId))
-            .map((nodeId) => [nodeId, true]),
-        ) as Record<NodeId, true>;
-        if (
-          Object.keys(filtered).length !== Object.keys(hiddenNodeIds).length
-        ) {
-          changed = true;
-        }
-        if (Object.keys(filtered).length > 0) {
-          next[treeId as UIDesignImageId] = filtered;
-        }
+    const validNodeIds = new Set<NodeId>();
+    for (const tree of editor.state.ui_trees) {
+      for (const nodeId of collectUiNodeIds(tree.root)) {
+        validNodeIds.add(nodeId);
       }
-      return changed ? next : current;
+    }
+    setHiddenNodeIds((current) => {
+      const next = new Set(
+        [...current].filter((nodeId) => validNodeIds.has(nodeId)),
+      );
+      return next.size === current.size ? current : next;
     });
   }, [editor.state.ui_trees]);
 
-  const hiddenNodeIds = useMemo<ReadonlySet<NodeId>>(
-    () =>
-      new Set(
-        activeImageId
-          ? Object.keys(hiddenNodeIdsByImage[activeImageId] ?? {})
-          : [],
-      ),
-    [activeImageId, hiddenNodeIdsByImage],
-  );
-
   const isNodePreviewVisible = useCallback(
-    (nodeId: NodeId, treeId = activeImageId) =>
-      !(treeId ? hiddenNodeIdsByImage[treeId]?.[nodeId] : false),
-    [activeImageId, hiddenNodeIdsByImage],
+    (nodeId: NodeId) => !hiddenNodeIds.has(nodeId),
+    [hiddenNodeIds],
   );
 
   const setNodePreviewVisible = useCallback(
-    (nodeId: NodeId, visible: boolean, treeId = activeImageId) => {
-      if (!treeId) return;
-      setHiddenNodeIdsByImage((current) => {
-        const currentForImage = current[treeId] ?? {};
-        const currentlyVisible = !currentForImage[nodeId];
+    (nodeId: NodeId, visible: boolean) => {
+      setHiddenNodeIds((current) => {
+        const currentlyVisible = !current.has(nodeId);
         if (currentlyVisible === visible) return current;
-        const nextForImage = { ...currentForImage };
-        if (visible) delete nextForImage[nodeId];
-        else nextForImage[nodeId] = true;
-        const next = { ...current };
-        if (Object.keys(nextForImage).length > 0) {
-          next[treeId] = nextForImage;
-        } else {
-          delete next[treeId];
-        }
+        const next = new Set(current);
+        if (visible) next.delete(nodeId);
+        else next.add(nodeId);
         return next;
       });
     },
-    [activeImageId],
+    [],
   );
 
   const toggleNodePreviewVisibility = useCallback(
-    (nodeId: NodeId, treeId = activeImageId) => {
-      setNodePreviewVisible(
-        nodeId,
-        !isNodePreviewVisible(nodeId, treeId),
-        treeId,
-      );
+    (nodeId: NodeId) => {
+      setNodePreviewVisible(nodeId, !isNodePreviewVisible(nodeId));
     },
-    [activeImageId, isNodePreviewVisible, setNodePreviewVisible],
+    [isNodePreviewVisible, setNodePreviewVisible],
   );
 
   const findNodeContext = useCallback(function findNodeContext(
@@ -460,12 +413,6 @@ export function useUiEditorPage(
     if (id === selectedSpriteId) setSelectedSpriteId(null);
     if (id === selectedFontId) setSelectedFontId(null);
     if (id !== activeImageId) return;
-    setHiddenNodeIdsByImage((current) => {
-      if (!(id in current)) return current;
-      const next = { ...current };
-      delete next[id as UIDesignImageId];
-      return next;
-    });
     setSelectedNodeId(null);
     const index = imageOrder.indexOf(id);
     const remaining = imageOrder.filter((item) => item !== id);
@@ -598,7 +545,7 @@ export function useUiEditorPage(
     setActiveImageId(null);
     setSelectedSpriteId(null);
     setSelectedNodeId(null);
-    setHiddenNodeIdsByImage({});
+    setHiddenNodeIds(new Set());
     setPreviewUrls({});
     setClearOpen(false);
   }
@@ -687,20 +634,8 @@ export function useUiEditorPage(
     return result;
   }
 
-  function moveNode(
-    sourceTreeId: UIDesignImageId,
-    targetTreeId: UIDesignImageId,
-    nodeId: NodeId,
-    targetParentId: NodeId,
-    targetIndex: number,
-  ) {
-    const result = editor.moveNode(
-      sourceTreeId,
-      targetTreeId,
-      nodeId,
-      targetParentId,
-      targetIndex,
-    );
+  function moveNode(request: UiNodeMoveRequest) {
+    const result = editor.moveNode(request);
     if (!result.ok) {
       setStatus(
         result.reason === 'locked'
@@ -928,7 +863,6 @@ export function useUiEditorPage(
     activeImage,
     selectedSprite,
     selectedFont,
-    hiddenNodeIdsByImage,
     hiddenNodeIds,
     isNodePreviewVisible,
     setNodePreviewVisible,
diff --git a/apps/ai-game-creator-shell/tests/uiEditorPage.test.ts b/apps/ai-game-creator-shell/tests/uiEditorPage.test.ts
index 7acd1e907..01f717feb 100644
--- a/apps/ai-game-creator-shell/tests/uiEditorPage.test.ts
+++ b/apps/ai-game-creator-shell/tests/uiEditorPage.test.ts
@@ -158,7 +158,7 @@ describe('UiEditorPage', () => {
     expect(result.current.selectedSpriteId).toBe('panel');
   });
 
-  it('keeps node preview visibility transient and scoped to each interface image', () => {
+  it('keeps node preview visibility transient and attached to global node IDs', () => {
     const { result } = renderHook(() => useUiEditorPage('/tmp/ui-editor'));
     act(() => {
       result.current.editor.addDesignImages([
@@ -209,7 +209,7 @@ describe('UiEditorPage', () => {
     expect(JSON.stringify(result.current.editor.state)).toBe(stateBeforeToggle);
 
     act(() => result.current.selectDesignImage('page-b'));
-    expect(result.current.hiddenNodeIds.size).toBe(0);
+    expect(result.current.hiddenNodeIds.has(rootId)).toBe(true);
 
     act(() => result.current.selectDesignImage('page-a'));
     expect(result.current.hiddenNodeIds.has(rootId)).toBe(true);
diff --git a/apps/ai-game-creator-shell/tests/uiEditorState.test.ts b/apps/ai-game-creator-shell/tests/uiEditorState.test.ts
index 9435efccf..b1895c657 100644
--- a/apps/ai-game-creator-shell/tests/uiEditorState.test.ts
+++ b/apps/ai-game-creator-shell/tests/uiEditorState.test.ts
@@ -122,7 +122,13 @@ describe('useUiEditorState', () => {
 
     act(() => {
       expect(
-        result.current.moveNode('source', 'target', 'moved', 'target-root', 0),
+        result.current.moveNode({
+          sourceTreeId: 'source',
+          targetTreeId: 'target',
+          nodeId: 'moved',
+          targetParentId: 'target-root',
+          targetIndex: 0,
+        }),
       ).toEqual({ ok: true, value: undefined });
     });
 
@@ -133,6 +139,72 @@ describe('useUiEditorState', () => {
     });
   });
 
+  it('keeps page position stable when reparenting within one UI tree', () => {
+    const moved = nodeWithSprite('moved');
+    moved.transform = {
+      anchor_min: [0, 0],
+      anchor_max: [1, 1],
+      offset_min: [0, 0],
+      offset_max: [0, 0],
+    };
+    const initial: State = {
+      ...structuredClone(EMPTY_UI_EDITOR_STATE),
+      ui_design_images: { page: image('Page') },
+      ui_trees: [
+        {
+          src_ui_design: 'page',
+          root: pageRoot('page-root', [
+            {
+              ...pageRoot('source-parent'),
+              transform: {
+                anchor_min: [0, 0],
+                anchor_max: [0.5, 0.5],
+                offset_min: [0, 0],
+                offset_max: [0, 0],
+              },
+              children: [moved],
+            },
+            {
+              ...pageRoot('target-parent'),
+              transform: {
+                anchor_min: [0.5, 0.5],
+                anchor_max: [1, 1],
+                offset_min: [0, 0],
+                offset_max: [0, 0],
+              },
+            },
+          ]),
+        },
+      ],
+    };
+    const { result } = renderHook(() => useUiEditorState(initial));
+
+    act(() => {
+      expect(
+        result.current.moveNode({
+          sourceTreeId: 'page',
+          targetTreeId: 'page',
+          nodeId: 'moved',
+          targetParentId: 'target-parent',
+          targetIndex: 0,
+        }),
+      ).toEqual({ ok: true, value: undefined });
+    });
+
+    expect(
+      result.current.state.ui_trees[0]?.root.children[0]?.children,
+    ).toEqual([]);
+    expect(
+      result.current.state.ui_trees[0]?.root.children[1]?.children[0]
+        ?.transform,
+    ).toMatchObject({
+      anchor_min: [0, 0],
+      anchor_max: [1, 1],
+      offset_min: [-50, -40],
+      offset_max: [-50, -40],
+    });
+  });
+
   it('exposes focused operations over one shared state', () => {
     const { result } = renderHook(() => useUiEditorState());