diff --git a/electron/main-window.ts b/electron/main-window.ts
index 32f5aebc6a..1261953edd 100644
--- a/electron/main-window.ts
+++ b/electron/main-window.ts
@@ -259,6 +259,19 @@ export const createWindow = async ({
     }
   });
 
+  // Notify renderer of fullscreen state changes (used for app border visibility)
+  mainWin.on('enter-full-screen', () => {
+    mainWin.webContents.send(IPC.ENTER_FULL_SCREEN);
+  });
+  mainWin.on('leave-full-screen', () => {
+    mainWin.webContents.send(IPC.LEAVE_FULL_SCREEN);
+  });
+  mainWin.webContents.on('did-finish-load', () => {
+    if (mainWin.isFullScreen()) {
+      mainWin.webContents.send(IPC.ENTER_FULL_SCREEN);
+    }
+  });
+
   // Listen for theme changes to update title bar overlay color and symbol
   if (isUseCustomWindowTitleBar && !IS_MAC) {
     ipcMain.on(IPC.UPDATE_TITLE_BAR_DARK_MODE, (ev, isDarkMode: boolean) => {
diff --git a/electron/shared-with-frontend/ipc-events.const.ts b/electron/shared-with-frontend/ipc-events.const.ts
index 60413d08fe..7ca8751bb1 100644
--- a/electron/shared-with-frontend/ipc-events.const.ts
+++ b/electron/shared-with-frontend/ipc-events.const.ts
@@ -53,6 +53,8 @@ export enum IPC {
   ANY_FILE_DOWNLOADED = 'ANY_FILE_DOWNLOADED',
 
   FULL_SCREEN_BLOCKER = 'FULL_SCREEN_BLOCKER',
+  ENTER_FULL_SCREEN = 'ENTER_FULL_SCREEN',
+  LEAVE_FULL_SCREEN = 'LEAVE_FULL_SCREEN',
 
   GET_PATH = 'GET_PATH',
   GET_BACKUP_PATH = 'GET_BACKUP_PATH',
diff --git a/src/app/app.constants.ts b/src/app/app.constants.ts
index 0ca9ef3833..0cf25ff48b 100644
--- a/src/app/app.constants.ts
+++ b/src/app/app.constants.ts
@@ -44,6 +44,7 @@ export enum BodyClass {
 
   isAndroidKeyboardShown = 'isAndroidKeyboardShown',
   isAndroidKeyboardHidden = 'isAndroidKeyboardHidden',
+  isFullScreen = 'isFullScreen',
   isAddTaskBarOpen = 'isAddTaskBarOpen',
 
   // iOS-specific classes
diff --git a/src/app/core/ipc-events.ts b/src/app/core/ipc-events.ts
index bef76d8221..01010af4e0 100644
--- a/src/app/core/ipc-events.ts
+++ b/src/app/core/ipc-events.ts
@@ -24,6 +24,13 @@ export const ipcSuspend$: Observable<unknown> = IS_ELECTRON
   ? ipcEvent$(IPC.SUSPEND).pipe()
   : EMPTY;
 
+export const ipcEnterFullScreen$: Observable<unknown> = IS_ELECTRON
+  ? ipcEvent$(IPC.ENTER_FULL_SCREEN).pipe()
+  : EMPTY;
+export const ipcLeaveFullScreen$: Observable<unknown> = IS_ELECTRON
+  ? ipcEvent$(IPC.LEAVE_FULL_SCREEN).pipe()
+  : EMPTY;
+
 export const ipcShowAddTaskBar$: Observable<unknown> = IS_ELECTRON
   ? ipcEvent$(IPC.SHOW_ADD_TASK_BAR).pipe()
   : EMPTY;
diff --git a/src/app/core/theme/global-theme.service.ts b/src/app/core/theme/global-theme.service.ts
index df9d643fbf..eb874af70f 100644
--- a/src/app/core/theme/global-theme.service.ts
+++ b/src/app/core/theme/global-theme.service.ts
@@ -26,6 +26,7 @@ import { combineLatest, fromEvent, Observable, of } from 'rxjs';
 import { IS_FIREFOX } from '../../util/is-firefox';
 import { ImexViewService } from '../../imex/imex-meta/imex-view.service';
 import { IS_MOUSE_PRIMARY, IS_TOUCH_PRIMARY } from '../../util/is-mouse-primary';
+import { ipcEnterFullScreen$, ipcLeaveFullScreen$ } from '../ipc-events';
 
 import { IS_ANDROID_WEB_VIEW } from '../../util/is-android-web-view';
 import { androidInterface } from '../../features/android/android-interface';
@@ -282,6 +283,12 @@ export class GlobalThemeService {
       this.document.body.classList.add(BodyClass.isElectron);
       this.document.body.classList.add(BodyClass.isAdvancedFeatures);
       this.document.body.classList.remove(BodyClass.isNoAdvancedFeatures);
+      ipcEnterFullScreen$.pipe(takeUntilDestroyed(this._destroyRef)).subscribe(() => {
+        this.document.body.classList.add(BodyClass.isFullScreen);
+      });
+      ipcLeaveFullScreen$.pipe(takeUntilDestroyed(this._destroyRef)).subscribe(() => {
+        this.document.body.classList.remove(BodyClass.isFullScreen);
+      });
     } else {
       this.document.body.classList.add(BodyClass.isWeb);
       this._chromeExtensionInterfaceService.onReady$.pipe(take(1)).subscribe(() => {
diff --git a/src/styles/page.scss b/src/styles/page.scss
index 5304c0444c..7467df50f8 100644
--- a/src/styles/page.scss
+++ b/src/styles/page.scss
@@ -122,7 +122,7 @@ body {
     }
   }
 
-  &.isObsidianStyleHeader.isElectron {
+  &.isElectron:not(.isFullScreen) {
     border: 1px solid var(--divider-color);
   }
 }