diff --git a/src/main/ipc/handlers.ts b/src/main/ipc/handlers.ts
index 7078b8c..89a582d 100644
--- a/src/main/ipc/handlers.ts
+++ b/src/main/ipc/handlers.ts
@@ -1,4 +1,4 @@
-import { app, ipcMain, dialog, shell } from 'electron';
+import { app, BrowserWindow, ipcMain, dialog, shell } from 'electron';
 import * as path from 'path';
 import * as fsPromises from 'fs/promises';
 import { eq } from 'drizzle-orm';
@@ -697,6 +697,20 @@ export function registerIpcHandlers(): void {
     return projectEngine.getDefaultProjectBaseDir(projectId);
   });
 
+  safeHandle('app:getTitleBarMetrics', async (event) => {
+    const ownerWindow = BrowserWindow.fromWebContents(event.sender);
+    const buttonPosition = ownerWindow?.getWindowButtonPosition?.();
+    if (!buttonPosition) {
+      return null;
+    }
+
+    const estimatedClusterWidth = Math.max(52, Math.round(buttonPosition.y * 4));
+    const trailingPadding = Math.max(8, Math.round(buttonPosition.y * 0.6));
+    const macosLeftInset = Math.max(0, Math.round(buttonPosition.x + estimatedClusterWidth + trailingPadding));
+
+    return { macosLeftInset };
+  });
+
   safeHandle('app:showItemInFolder', async (_, itemPath: string) => {
     return shell.showItemInFolder(itemPath);
   });
diff --git a/src/main/preload.ts b/src/main/preload.ts
index fb2d8a6..f684544 100644
--- a/src/main/preload.ts
+++ b/src/main/preload.ts
@@ -137,6 +137,7 @@ export const electronAPI: ElectronAPI = {
   // App
   app: {
     getDataPaths: () => ipcRenderer.invoke('app:getDataPaths'),
+    getTitleBarMetrics: () => ipcRenderer.invoke('app:getTitleBarMetrics'),
     openFolder: (folderPath: string) => ipcRenderer.invoke('app:openFolder', folderPath),
     showItemInFolder: (itemPath: string) => ipcRenderer.invoke('app:showItemInFolder', itemPath),
     selectFolder: (title?: string) => ipcRenderer.invoke('app:selectFolder', title),
diff --git a/src/main/shared/electronApi.ts b/src/main/shared/electronApi.ts
index 4637263..4e0b82f 100644
--- a/src/main/shared/electronApi.ts
+++ b/src/main/shared/electronApi.ts
@@ -505,6 +505,7 @@ export interface ElectronAPI {
   };
   app: {
     getDataPaths: () => Promise<{ database: string; posts: string; media: string }>;
+    getTitleBarMetrics: () => Promise<{ macosLeftInset: number } | null>;
     openFolder: (folderPath: string) => Promise<string>;
     showItemInFolder: (itemPath: string) => Promise<void>;
     selectFolder: (title?: string) => Promise<string | null>;
diff --git a/src/renderer/components/WindowTitleBar/WindowTitleBar.css b/src/renderer/components/WindowTitleBar/WindowTitleBar.css
index fd49ab8..3afa2bc 100644
--- a/src/renderer/components/WindowTitleBar/WindowTitleBar.css
+++ b/src/renderer/components/WindowTitleBar/WindowTitleBar.css
@@ -23,6 +23,10 @@
   z-index: 2;
 }
 
+.window-titlebar.is-mac .window-titlebar-menu-bar {
+  margin-left: max(var(--bds-titlebar-macos-left-inset, 78px), calc(6px + var(--bds-titlebar-overlay-left, 0px)));
+}
+
 .window-titlebar-menu-button {
   height: 24px;
   border: none;
diff --git a/src/renderer/components/WindowTitleBar/WindowTitleBar.tsx b/src/renderer/components/WindowTitleBar/WindowTitleBar.tsx
index 654a832..24935c8 100644
--- a/src/renderer/components/WindowTitleBar/WindowTitleBar.tsx
+++ b/src/renderer/components/WindowTitleBar/WindowTitleBar.tsx
@@ -133,6 +133,83 @@ export const WindowTitleBar: React.FC = () => {
     };
   }, []);
 
+  useEffect(() => {
+    if (!isMac) {
+      return;
+    }
+
+    const rootStyle = document.documentElement.style;
+    let isDisposed = false;
+    let resolutionQuery: MediaQueryList | null = null;
+
+    const syncMacInset = async () => {
+      const metrics = await window.electronAPI?.app?.getTitleBarMetrics?.();
+      if (isDisposed) {
+        return;
+      }
+
+      if (metrics && Number.isFinite(metrics.macosLeftInset)) {
+        rootStyle.setProperty('--bds-titlebar-macos-left-inset', `${Math.max(0, Math.round(metrics.macosLeftInset))}px`);
+      }
+    };
+
+    const bindResolutionListener = () => {
+      if (typeof window.matchMedia !== 'function') {
+        return;
+      }
+
+      if (resolutionQuery && typeof resolutionQuery.removeEventListener === 'function') {
+        resolutionQuery.removeEventListener('change', onResolutionChange);
+      }
+
+      resolutionQuery = window.matchMedia(`(resolution: ${window.devicePixelRatio}dppx)`);
+      if (typeof resolutionQuery.addEventListener === 'function') {
+        resolutionQuery.addEventListener('change', onResolutionChange);
+      }
+    };
+
+    const onResolutionChange = () => {
+      void syncMacInset();
+      bindResolutionListener();
+    };
+
+    const onResize = () => {
+      void syncMacInset();
+    };
+
+    const onVisibilityChange = () => {
+      if (!document.hidden) {
+        void syncMacInset();
+      }
+    };
+
+    const canListenToWindowEvents = typeof window.addEventListener === 'function';
+    const canListenToDocumentEvents = typeof document.addEventListener === 'function';
+
+    void syncMacInset();
+    bindResolutionListener();
+    if (canListenToWindowEvents) {
+      window.addEventListener('resize', onResize);
+    }
+    if (canListenToDocumentEvents) {
+      document.addEventListener('visibilitychange', onVisibilityChange);
+    }
+
+    return () => {
+      isDisposed = true;
+      if (canListenToWindowEvents && typeof window.removeEventListener === 'function') {
+        window.removeEventListener('resize', onResize);
+      }
+      if (canListenToDocumentEvents && typeof document.removeEventListener === 'function') {
+        document.removeEventListener('visibilitychange', onVisibilityChange);
+      }
+
+      if (resolutionQuery && typeof resolutionQuery.removeEventListener === 'function') {
+        resolutionQuery.removeEventListener('change', onResolutionChange);
+      }
+    };
+  }, [isMac]);
+
   useEffect(() => {
     const updateTitle = () => {
       setWindowTitle(document.title || 'Blogging Desktop Server');
@@ -383,7 +460,7 @@ export const WindowTitleBar: React.FC = () => {
   const activeMenu = openMenu ? visibleMenuGroups.find(group => group.label === openMenu.label) : null;
 
   return (
-    <div className="window-titlebar" data-testid="window-titlebar" ref={menuRootRef}>
+    <div className={`window-titlebar${isMac ? ' is-mac' : ''}`} data-testid="window-titlebar" ref={menuRootRef}>
       <div className="window-titlebar-menu-bar" data-testid="window-titlebar-menu-bar">
         {visibleMenuGroups.map(group => (
           <button
diff --git a/tests/ipc/handlers.test.ts b/tests/ipc/handlers.test.ts
index 6d70b3b..efa24aa 100644
--- a/tests/ipc/handlers.test.ts
+++ b/tests/ipc/handlers.test.ts
@@ -19,6 +19,9 @@ vi.mock('electron', () => ({
   app: {
     quit: vi.fn(),
   },
+  BrowserWindow: {
+    fromWebContents: vi.fn(),
+  },
   ipcMain: {
     handle: vi.fn((channel: string, handler: (...args: any[]) => Promise<any>) => {
       registeredHandlers.set(channel, handler);
@@ -1344,6 +1347,25 @@ describe('IPC Handlers', () => {
       });
     });
 
+    describe('app:getTitleBarMetrics', () => {
+      it('should return dynamic macOS title bar left inset from native window button position', async () => {
+        const { BrowserWindow } = await import('electron');
+        const sender = {};
+        const event = { sender };
+
+        vi.mocked(BrowserWindow.fromWebContents).mockReturnValue({
+          getWindowButtonPosition: vi.fn(() => ({ x: 14, y: 14 })),
+        } as unknown as ReturnType<typeof BrowserWindow.fromWebContents>);
+
+        const result = await invokeHandlerWithEvent(event, 'app:getTitleBarMetrics');
+
+        expect(BrowserWindow.fromWebContents).toHaveBeenCalledWith(sender);
+        expect(result).toEqual({
+          macosLeftInset: 78,
+        });
+      });
+    });
+
     describe('app:triggerMenuAction', () => {
       it('should forward custom titlebar action to renderer menu channel', async () => {
         const send = vi.fn();
diff --git a/tests/renderer/components/WindowTitleBar.test.tsx b/tests/renderer/components/WindowTitleBar.test.tsx
index 1832d3d..f7db61b 100644
--- a/tests/renderer/components/WindowTitleBar.test.tsx
+++ b/tests/renderer/components/WindowTitleBar.test.tsx
@@ -5,13 +5,53 @@ import { WindowTitleBar } from '../../../src/renderer/components/WindowTitleBar/
 import { useAppStore } from '../../../src/renderer/store';
 
 describe('WindowTitleBar', () => {
+  const originalNavigatorPlatform = navigator.platform;
+
   beforeEach(() => {
+    Object.defineProperty(navigator, 'platform', {
+      value: originalNavigatorPlatform,
+      configurable: true,
+    });
+
     useAppStore.setState({
       sidebarVisible: true,
       panelVisible: false,
     });
   });
 
+  it('applies a macOS class to the title bar root for platform-specific spacing', () => {
+    Object.defineProperty(navigator, 'platform', {
+      value: 'MacIntel',
+      configurable: true,
+    });
+
+    render(<WindowTitleBar />);
+
+    expect(screen.getByTestId('window-titlebar')).toHaveClass('is-mac');
+  });
+
+  it('sets macOS title bar inset CSS variable from dynamic native metrics', async () => {
+    Object.defineProperty(navigator, 'platform', {
+      value: 'MacIntel',
+      configurable: true,
+    });
+
+    const getTitleBarMetrics = vi.fn().mockResolvedValue({ macosLeftInset: 102 });
+    window.electronAPI.app = {
+      ...(window.electronAPI.app || {}),
+      getTitleBarMetrics,
+    };
+
+    render(<WindowTitleBar />);
+
+    await act(async () => {
+      await Promise.resolve();
+    });
+
+    expect(getTitleBarMetrics).toHaveBeenCalled();
+    expect(document.documentElement.style.getPropertyValue('--bds-titlebar-macos-left-inset')).toBe('102px');
+  });
+
   it('renders a right-side sidebar toggle button and toggles store state', () => {
     render(<WindowTitleBar />);