diff --git a/apps/ai-game-creator-shell/tests/previewWorkspaceZoom.test.tsx b/apps/ai-game-creator-shell/tests/previewWorkspaceZoom.test.tsx
index 908086f1d..50a89c1e2 100644
--- a/apps/ai-game-creator-shell/tests/previewWorkspaceZoom.test.tsx
+++ b/apps/ai-game-creator-shell/tests/previewWorkspaceZoom.test.tsx
@@ -87,13 +87,17 @@ function createCanvas(
   };
 }
 
-function renderedScale(container: HTMLElement) {
-  const transform = (
-    container.querySelector('.genarrative-image-canvas__world') as HTMLElement
-  ).style.transform;
-  const scale = /scale\(([^)]+)\)/.exec(transform)?.[1];
-  if (!scale) throw new Error(`无法从 ${transform} 读取缩放值`);
-  return Number(scale);
+function logicalViewportScale(container: HTMLElement) {
+  const world = container.querySelector(
+    '.genarrative-image-canvas__world',
+  ) as HTMLElement;
+  const inverseScale = Number(
+    world.style.getPropertyValue('--genarrative-image-canvas-inverse-scale'),
+  );
+  if (!Number.isFinite(inverseScale) || inverseScale <= 0) {
+    throw new Error(`无法从 world 读取逻辑缩放值`);
+  }
+  return 1 / inverseScale;
 }
 
 beforeEach(() => {
@@ -110,7 +114,7 @@ describe('PreviewWorkspace quick zoom', () => {
   it('uses the toolbar zoom step while the preview is hovered', () => {
     const rendered = render(<PreviewWorkspace canvas={createCanvas()} />);
     const preview = screen.getByRole('region', { name: 'UI 预览画布' });
-    const before = renderedScale(rendered.container);
+    const before = logicalViewportScale(rendered.container);
 
     fireEvent.pointerEnter(preview);
     const wasNotCancelled = fireEvent.keyDown(window, {
@@ -121,14 +125,14 @@ describe('PreviewWorkspace quick zoom', () => {
     });
 
     expect(wasNotCancelled).toBe(false);
-    expect(renderedScale(rendered.container)).toBeCloseTo(before * 1.16);
+    expect(logicalViewportScale(rendered.container)).toBeCloseTo(before * 1.16);
   });
 
   it('requires hover or focus and ignores interactive targets', () => {
     const rendered = render(<PreviewWorkspace canvas={createCanvas()} />);
     const preview = screen.getByRole('region', { name: 'UI 预览画布' });
     const zoomButton = screen.getByRole('button', { name: '放大画布' });
-    const initial = renderedScale(rendered.container);
+    const initial = logicalViewportScale(rendered.container);
 
     expect(
       fireEvent.keyDown(window, {
@@ -137,7 +141,7 @@ describe('PreviewWorkspace quick zoom', () => {
         cancelable: true,
       }),
     ).toBe(true);
-    expect(renderedScale(rendered.container)).toBe(initial);
+    expect(logicalViewportScale(rendered.container)).toBe(initial);
 
     fireEvent.pointerEnter(preview);
     expect(
@@ -147,7 +151,7 @@ describe('PreviewWorkspace quick zoom', () => {
         cancelable: true,
       }),
     ).toBe(true);
-    expect(renderedScale(rendered.container)).toBe(initial);
+    expect(logicalViewportScale(rendered.container)).toBe(initial);
 
     fireEvent.pointerLeave(preview);
     fireEvent.focus(preview);
@@ -157,13 +161,15 @@ describe('PreviewWorkspace quick zoom', () => {
       ctrlKey: true,
       cancelable: true,
     });
-    expect(renderedScale(rendered.container)).toBeCloseTo(initial * 0.86);
+    expect(logicalViewportScale(rendered.container)).toBeCloseTo(
+      initial * 0.86,
+    );
   });
 
   it('keeps actual-size and fit shortcuts within the preview scope', () => {
     const rendered = render(<PreviewWorkspace canvas={createCanvas()} />);
     const preview = screen.getByRole('region', { name: 'UI 预览画布' });
-    const fitted = renderedScale(rendered.container);
+    const fitted = logicalViewportScale(rendered.container);
 
     fireEvent.focus(preview);
     fireEvent.keyDown(window, {
@@ -171,14 +177,14 @@ describe('PreviewWorkspace quick zoom', () => {
       ctrlKey: true,
       cancelable: true,
     });
-    expect(renderedScale(rendered.container)).toBe(1);
+    expect(logicalViewportScale(rendered.container)).toBe(1);
 
     fireEvent.keyDown(window, {
       key: '0',
       ctrlKey: true,
       cancelable: true,
     });
-    expect(renderedScale(rendered.container)).toBe(fitted);
+    expect(logicalViewportScale(rendered.container)).toBe(fitted);
   });
 
   it('leaves browser zoom untouched when the preview has no content', () => {
diff --git a/docs/【交互设计】预览画布缩放滑杆-2026-09-05.md b/docs/【交互设计】预览画布缩放滑杆-2026-09-05.md
index 198d7788a..497fb7e85 100644
--- a/docs/【交互设计】预览画布缩放滑杆-2026-09-05.md
+++ b/docs/【交互设计】预览画布缩放滑杆-2026-09-05.md
@@ -19,6 +19,7 @@
 - 事件来自输入框、文本编辑区、按钮、链接、缩放工具栏或其他可操作控件时不拦截；不向 iframe 子文档注入监听。
 - 仅在存在可缩放视口且确认命中快捷键时调用 `preventDefault()` 与 `stopPropagation()`，防止浏览器页面同时缩放。
 - 保留现有 `Ctrl/Cmd+0` 适配画布与 `Ctrl/Cmd+1` 恢复 100% 行为，不增加其他重置快捷键。缩放仍是当前预览实例的临时 UI 状态。
+- 快捷键和百分比使用逻辑 `viewport.scale` 作为缩放真相；共享 `CanvasWorld` 的渲染 transform 可能包含超采样换算，验证时不得直接把 CSS transform 值当作用户可见比例。
 - 保留快捷键与缩放焦点边界的组件级回归测试，不扩展端到端测试。
 
 ## 验收