Fix Windows overlay tracking, z-order, and startup visibility

- switch Windows overlay tracking to native win32 polling with native owner and z-order helpers - keep the visible overlay and stats overlay aligned across focus handoff, transient tracker misses, and minimize/restore cycles - start the visible overlay click-through and hide the initial opaque startup frame until the tracked transparent state settles - add a backlog task for the inconsistent mpv y-t overlay toggle after menu toggles
2026-04-10 04:19:25 -07:00 · 2026-04-10 01:00:53 -07:00
parent ac25213255
commit 7698258f61
35 changed files with 2658 additions and 230 deletions
--- a/src/core/services/index.ts
+++ b/src/core/services/index.ts
@@ -72,6 +72,7 @@ export {
  createOverlayWindow,
  enforceOverlayLayerOrder,
  ensureOverlayWindowLevel,
+  isOverlayWindowContentReady,
  syncOverlayWindowLayer,
  updateOverlayWindowBounds,
 } from './overlay-window';
--- a/src/core/services/overlay-runtime-init.test.ts
+++ b/src/core/services/overlay-runtime-init.test.ts
@@ -443,3 +443,214 @@ test('initializeOverlayRuntime refreshes visible overlay when tracker focus chan

  assert.equal(visibilityRefreshCalls, 2);
 });
+
+test('initializeOverlayRuntime refreshes the current subtitle when tracker finds the target window again', () => {
+  let subtitleRefreshCalls = 0;
+  const tracker = {
+    onGeometryChange: null as ((...args: unknown[]) => void) | null,
+    onWindowFound: null as ((...args: unknown[]) => void) | null,
+    onWindowLost: null as (() => void) | null,
+    onWindowFocusChange: null as ((focused: boolean) => void) | null,
+    start: () => {},
+  };
+
+  initializeOverlayRuntime({
+    backendOverride: null,
+    createMainWindow: () => {},
+    registerGlobalShortcuts: () => {},
+    updateVisibleOverlayBounds: () => {},
+    isVisibleOverlayVisible: () => true,
+    updateVisibleOverlayVisibility: () => {},
+    refreshCurrentSubtitle: () => {
+      subtitleRefreshCalls += 1;
+    },
+    getOverlayWindows: () => [],
+    syncOverlayShortcuts: () => {},
+    setWindowTracker: () => {},
+    getMpvSocketPath: () => '/tmp/mpv.sock',
+    createWindowTracker: () => tracker as never,
+    getResolvedConfig: () => ({
+      ankiConnect: { enabled: false } as never,
+    }),
+    getSubtitleTimingTracker: () => null,
+    getMpvClient: () => null,
+    getRuntimeOptionsManager: () => null,
+    setAnkiIntegration: () => {},
+    showDesktopNotification: () => {},
+    createFieldGroupingCallback: () => async () => ({
+      keepNoteId: 1,
+      deleteNoteId: 2,
+      deleteDuplicate: false,
+      cancelled: false,
+    }),
+    getKnownWordCacheStatePath: () => '/tmp/known-words-cache.json',
+  });
+
+  tracker.onWindowFound?.({ x: 100, y: 200, width: 1280, height: 720 });
+
+  assert.equal(subtitleRefreshCalls, 1);
+});
+
+test('initializeOverlayRuntime hides overlay windows when tracker loses the target window', () => {
+  const calls: string[] = [];
+  const tracker = {
+    onGeometryChange: null as ((...args: unknown[]) => void) | null,
+    onWindowFound: null as ((...args: unknown[]) => void) | null,
+    onWindowLost: null as (() => void) | null,
+    onWindowFocusChange: null as ((focused: boolean) => void) | null,
+    isTargetWindowMinimized: () => true,
+    start: () => {},
+  };
+  const overlayWindows = [
+    {
+      hide: () => calls.push('hide-visible'),
+    },
+    {
+      hide: () => calls.push('hide-modal'),
+    },
+  ];
+
+  initializeOverlayRuntime({
+    backendOverride: null,
+    createMainWindow: () => {},
+    registerGlobalShortcuts: () => {},
+    updateVisibleOverlayBounds: () => {},
+    isVisibleOverlayVisible: () => true,
+    updateVisibleOverlayVisibility: () => {},
+    refreshCurrentSubtitle: () => {},
+    getOverlayWindows: () => overlayWindows as never,
+    syncOverlayShortcuts: () => {
+      calls.push('sync-shortcuts');
+    },
+    setWindowTracker: () => {},
+    getMpvSocketPath: () => '/tmp/mpv.sock',
+    createWindowTracker: () => tracker as never,
+    getResolvedConfig: () => ({
+      ankiConnect: { enabled: false } as never,
+    }),
+    getSubtitleTimingTracker: () => null,
+    getMpvClient: () => null,
+    getRuntimeOptionsManager: () => null,
+    setAnkiIntegration: () => {},
+    showDesktopNotification: () => {},
+    createFieldGroupingCallback: () => async () => ({
+      keepNoteId: 1,
+      deleteNoteId: 2,
+      deleteDuplicate: false,
+      cancelled: false,
+    }),
+    getKnownWordCacheStatePath: () => '/tmp/known-words-cache.json',
+  });
+
+  tracker.onWindowLost?.();
+
+  assert.deepEqual(calls, ['hide-visible', 'hide-modal', 'sync-shortcuts']);
+});
+
+test('initializeOverlayRuntime preserves visible overlay on Windows tracker loss when target is not minimized', () => {
+  const calls: string[] = [];
+  const tracker = {
+    onGeometryChange: null as ((...args: unknown[]) => void) | null,
+    onWindowFound: null as ((...args: unknown[]) => void) | null,
+    onWindowLost: null as (() => void) | null,
+    onWindowFocusChange: null as ((focused: boolean) => void) | null,
+    isTargetWindowMinimized: () => false,
+    start: () => {},
+  };
+  const overlayWindows = [
+    {
+      hide: () => calls.push('hide-visible'),
+    },
+  ];
+
+  initializeOverlayRuntime({
+    backendOverride: null,
+    createMainWindow: () => {},
+    registerGlobalShortcuts: () => {},
+    updateVisibleOverlayBounds: () => {},
+    isVisibleOverlayVisible: () => true,
+    updateVisibleOverlayVisibility: () => {
+      calls.push('update-visible');
+    },
+    refreshCurrentSubtitle: () => {},
+    getOverlayWindows: () => overlayWindows as never,
+    syncOverlayShortcuts: () => {
+      calls.push('sync-shortcuts');
+    },
+    setWindowTracker: () => {},
+    getMpvSocketPath: () => '/tmp/mpv.sock',
+    createWindowTracker: () => tracker as never,
+    getResolvedConfig: () => ({
+      ankiConnect: { enabled: false } as never,
+    }),
+    getSubtitleTimingTracker: () => null,
+    getMpvClient: () => null,
+    getRuntimeOptionsManager: () => null,
+    setAnkiIntegration: () => {},
+    showDesktopNotification: () => {},
+    createFieldGroupingCallback: () => async () => ({
+      keepNoteId: 1,
+      deleteNoteId: 2,
+      deleteDuplicate: false,
+      cancelled: false,
+    }),
+    getKnownWordCacheStatePath: () => '/tmp/known-words-cache.json',
+  });
+
+  calls.length = 0;
+  tracker.onWindowLost?.();
+
+  assert.deepEqual(calls, ['sync-shortcuts']);
+});
+
+test('initializeOverlayRuntime restores overlay bounds and visibility when tracker finds the target window again', () => {
+  const bounds: Array<{ x: number; y: number; width: number; height: number }> = [];
+  let visibilityRefreshCalls = 0;
+  const tracker = {
+    onGeometryChange: null as ((...args: unknown[]) => void) | null,
+    onWindowFound: null as ((...args: unknown[]) => void) | null,
+    onWindowLost: null as (() => void) | null,
+    onWindowFocusChange: null as ((focused: boolean) => void) | null,
+    start: () => {},
+  };
+
+  initializeOverlayRuntime({
+    backendOverride: null,
+    createMainWindow: () => {},
+    registerGlobalShortcuts: () => {},
+    updateVisibleOverlayBounds: (geometry) => {
+      bounds.push(geometry);
+    },
+    isVisibleOverlayVisible: () => true,
+    updateVisibleOverlayVisibility: () => {
+      visibilityRefreshCalls += 1;
+    },
+    refreshCurrentSubtitle: () => {},
+    getOverlayWindows: () => [],
+    syncOverlayShortcuts: () => {},
+    setWindowTracker: () => {},
+    getMpvSocketPath: () => '/tmp/mpv.sock',
+    createWindowTracker: () => tracker as never,
+    getResolvedConfig: () => ({
+      ankiConnect: { enabled: false } as never,
+    }),
+    getSubtitleTimingTracker: () => null,
+    getMpvClient: () => null,
+    getRuntimeOptionsManager: () => null,
+    setAnkiIntegration: () => {},
+    showDesktopNotification: () => {},
+    createFieldGroupingCallback: () => async () => ({
+      keepNoteId: 1,
+      deleteNoteId: 2,
+      deleteDuplicate: false,
+      cancelled: false,
+    }),
+    getKnownWordCacheStatePath: () => '/tmp/known-words-cache.json',
+  });
+
+  const restoredGeometry = { x: 100, y: 200, width: 1280, height: 720 };
+  tracker.onWindowFound?.(restoredGeometry);
+
+  assert.deepEqual(bounds, [restoredGeometry]);
+  assert.equal(visibilityRefreshCalls, 2);
+});
--- a/src/core/services/overlay-runtime-init.ts
+++ b/src/core/services/overlay-runtime-init.ts
@@ -71,6 +71,7 @@ export function initializeOverlayRuntime(options: {
  updateVisibleOverlayBounds: (geometry: WindowGeometry) => void;
  isVisibleOverlayVisible: () => boolean;
  updateVisibleOverlayVisibility: () => void;
+  refreshCurrentSubtitle?: () => void;
  getOverlayWindows: () => BrowserWindow[];
  syncOverlayShortcuts: () => void;
  setWindowTracker: (tracker: BaseWindowTracker | null) => void;
@@ -78,6 +79,8 @@ export function initializeOverlayRuntime(options: {
    override?: string | null,
    targetMpvSocketPath?: string | null,
  ) => BaseWindowTracker | null;
+  bindOverlayOwner?: () => void;
+  releaseOverlayOwner?: () => void;
 }): void {
  options.createMainWindow();
  options.registerGlobalShortcuts();
@@ -94,11 +97,23 @@ export function initializeOverlayRuntime(options: {
    };
    windowTracker.onWindowFound = (geometry: WindowGeometry) => {
      options.updateVisibleOverlayBounds(geometry);
+      options.bindOverlayOwner?.();
      if (options.isVisibleOverlayVisible()) {
        options.updateVisibleOverlayVisibility();
+        options.refreshCurrentSubtitle?.();
      }
    };
    windowTracker.onWindowLost = () => {
+      options.releaseOverlayOwner?.();
+      if (
+        process.platform === 'win32' &&
+        typeof windowTracker.isTargetWindowMinimized === 'function' &&
+        !windowTracker.isTargetWindowMinimized()
+      ) {
+        options.syncOverlayShortcuts();
+        return;
+      }
+
      for (const window of options.getOverlayWindows()) {
        window.hide();
      }
--- a/src/core/services/overlay-visibility.test.ts
+++ b/src/core/services/overlay-visibility.test.ts
@@ -6,31 +6,59 @@ import { setVisibleOverlayVisible, updateVisibleOverlayVisibility } from './over
 type WindowTrackerStub = {
  isTracking: () => boolean;
  getGeometry: () => { x: number; y: number; width: number; height: number } | null;
+  isTargetWindowFocused?: () => boolean;
+  isTargetWindowMinimized?: () => boolean;
 };

 function createMainWindowRecorder() {
  const calls: string[] = [];
  let visible = false;
+  let focused = false;
+  let opacity = 1;
  const window = {
    isDestroyed: () => false,
    isVisible: () => visible,
+    isFocused: () => focused,
    hide: () => {
      visible = false;
+      focused = false;
      calls.push('hide');
    },
    show: () => {
      visible = true;
      calls.push('show');
    },
+    showInactive: () => {
+      visible = true;
+      calls.push('show-inactive');
+    },
    focus: () => {
+      focused = true;
      calls.push('focus');
    },
+    setAlwaysOnTop: (flag: boolean) => {
+      calls.push(`always-on-top:${flag}`);
+    },
    setIgnoreMouseEvents: (ignore: boolean, options?: { forward?: boolean }) => {
      calls.push(`mouse-ignore:${ignore}:${options?.forward === true ? 'forward' : 'plain'}`);
    },
+    setOpacity: (nextOpacity: number) => {
+      opacity = nextOpacity;
+      calls.push(`opacity:${nextOpacity}`);
+    },
+    moveTop: () => {
+      calls.push('move-top');
+    },
  };

-  return { window, calls };
+  return {
+    window,
+    calls,
+    getOpacity: () => opacity,
+    setFocused: (nextFocused: boolean) => {
+      focused = nextFocused;
+    },
+  };
 }

 test('macOS keeps visible overlay hidden while tracker is not ready and emits one loading OSD', () => {
@@ -167,7 +195,7 @@ test('untracked non-macOS overlay keeps fallback visible behavior when no tracke
  assert.ok(!calls.includes('osd'));
 });

-test('Windows visible overlay stays click-through and does not steal focus while tracked', () => {
+test('Windows visible overlay stays click-through and binds to mpv while tracked', () => {
  const { window, calls } = createMainWindowRecorder();
  const tracker: WindowTrackerStub = {
    isTracking: () => true,
@@ -186,6 +214,9 @@ test('Windows visible overlay stays click-through and does not steal focus while
    ensureOverlayWindowLevel: () => {
      calls.push('ensure-level');
    },
+    syncWindowsOverlayToMpvZOrder: () => {
+      calls.push('sync-windows-z-order');
+    },
    syncPrimaryOverlayWindowLayer: () => {
      calls.push('sync-layer');
    },
@@ -199,12 +230,58 @@ test('Windows visible overlay stays click-through and does not steal focus while
    isWindowsPlatform: true,
  } as never);

+  assert.ok(calls.includes('opacity:0'));
  assert.ok(calls.includes('mouse-ignore:true:forward'));
-  assert.ok(calls.includes('show'));
+  assert.ok(calls.includes('show-inactive'));
+  assert.ok(calls.includes('sync-windows-z-order'));
+  assert.ok(!calls.includes('move-top'));
+  assert.ok(!calls.includes('ensure-level'));
+  assert.ok(!calls.includes('enforce-order'));
  assert.ok(!calls.includes('focus'));
 });

-test('tracked Windows overlay refresh preserves renderer-managed mouse interaction when already visible', () => {
+test('Windows visible overlay restores opacity after the deferred reveal delay', async () => {
+  const { window, calls, getOpacity } = createMainWindowRecorder();
+  const tracker: WindowTrackerStub = {
+    isTracking: () => true,
+    getGeometry: () => ({ x: 0, y: 0, width: 1280, height: 720 }),
+  };
+
+  updateVisibleOverlayVisibility({
+    visibleOverlayVisible: true,
+    mainWindow: window as never,
+    windowTracker: tracker as never,
+    trackerNotReadyWarningShown: false,
+    setTrackerNotReadyWarningShown: () => {},
+    updateVisibleOverlayBounds: () => {
+      calls.push('update-bounds');
+    },
+    ensureOverlayWindowLevel: () => {
+      calls.push('ensure-level');
+    },
+    syncWindowsOverlayToMpvZOrder: () => {
+      calls.push('sync-windows-z-order');
+    },
+    syncPrimaryOverlayWindowLayer: () => {
+      calls.push('sync-layer');
+    },
+    enforceOverlayLayerOrder: () => {
+      calls.push('enforce-order');
+    },
+    syncOverlayShortcuts: () => {
+      calls.push('sync-shortcuts');
+    },
+    isMacOSPlatform: false,
+    isWindowsPlatform: true,
+  } as never);
+
+  assert.equal(getOpacity(), 0);
+  await new Promise<void>((resolve) => setTimeout(resolve, 60));
+  assert.equal(getOpacity(), 1);
+  assert.ok(calls.includes('opacity:1'));
+});
+
+test('tracked Windows overlay refresh rebinds while already visible', () => {
  const { window, calls } = createMainWindowRecorder();
  const tracker: WindowTrackerStub = {
    isTracking: () => true,
@@ -223,6 +300,9 @@ test('tracked Windows overlay refresh preserves renderer-managed mouse interacti
    ensureOverlayWindowLevel: () => {
      calls.push('ensure-level');
    },
+    syncWindowsOverlayToMpvZOrder: () => {
+      calls.push('sync-windows-z-order');
+    },
    syncPrimaryOverlayWindowLayer: () => {
      calls.push('sync-layer');
    },
@@ -250,6 +330,9 @@ test('tracked Windows overlay refresh preserves renderer-managed mouse interacti
    ensureOverlayWindowLevel: () => {
      calls.push('ensure-level');
    },
+    syncWindowsOverlayToMpvZOrder: () => {
+      calls.push('sync-windows-z-order');
+    },
    syncPrimaryOverlayWindowLayer: () => {
      calls.push('sync-layer');
    },
@@ -263,9 +346,11 @@ test('tracked Windows overlay refresh preserves renderer-managed mouse interacti
    isWindowsPlatform: true,
  } as never);

-  assert.ok(!calls.includes('mouse-ignore:true:forward'));
+  assert.ok(calls.includes('mouse-ignore:true:forward'));
+  assert.ok(calls.includes('sync-windows-z-order'));
+  assert.ok(!calls.includes('move-top'));
  assert.ok(!calls.includes('show'));
-  assert.ok(calls.includes('ensure-level'));
+  assert.ok(!calls.includes('ensure-level'));
  assert.ok(calls.includes('sync-shortcuts'));
 });

@@ -288,6 +373,9 @@ test('forced passthrough still reapplies while visible on Windows', () => {
    ensureOverlayWindowLevel: () => {
      calls.push('ensure-level');
    },
+    syncWindowsOverlayToMpvZOrder: () => {
+      calls.push('sync-windows-z-order');
+    },
    syncPrimaryOverlayWindowLayer: () => {
      calls.push('sync-layer');
    },
@@ -315,6 +403,9 @@ test('forced passthrough still reapplies while visible on Windows', () => {
    ensureOverlayWindowLevel: () => {
      calls.push('ensure-level');
    },
+    syncWindowsOverlayToMpvZOrder: () => {
+      calls.push('sync-windows-z-order');
+    },
    syncPrimaryOverlayWindowLayer: () => {
      calls.push('sync-layer');
    },
@@ -330,6 +421,286 @@ test('forced passthrough still reapplies while visible on Windows', () => {
  } as never);

  assert.ok(calls.includes('mouse-ignore:true:forward'));
+  assert.ok(!calls.includes('always-on-top:false'));
+  assert.ok(!calls.includes('move-top'));
+  assert.ok(calls.includes('sync-windows-z-order'));
+  assert.ok(!calls.includes('ensure-level'));
+  assert.ok(!calls.includes('enforce-order'));
+});
+
+test('forced passthrough still shows tracked overlay while bound to mpv on Windows', () => {
+  const { window, calls } = createMainWindowRecorder();
+  const tracker: WindowTrackerStub = {
+    isTracking: () => true,
+    getGeometry: () => ({ x: 0, y: 0, width: 1280, height: 720 }),
+  };
+
+  updateVisibleOverlayVisibility({
+    visibleOverlayVisible: true,
+    mainWindow: window as never,
+    windowTracker: tracker as never,
+    trackerNotReadyWarningShown: false,
+    setTrackerNotReadyWarningShown: () => {},
+    updateVisibleOverlayBounds: () => {
+      calls.push('update-bounds');
+    },
+    ensureOverlayWindowLevel: () => {
+      calls.push('ensure-level');
+    },
+    syncWindowsOverlayToMpvZOrder: () => {
+      calls.push('sync-windows-z-order');
+    },
+    syncPrimaryOverlayWindowLayer: () => {
+      calls.push('sync-layer');
+    },
+    enforceOverlayLayerOrder: () => {
+      calls.push('enforce-order');
+    },
+    syncOverlayShortcuts: () => {
+      calls.push('sync-shortcuts');
+    },
+    isMacOSPlatform: false,
+    isWindowsPlatform: true,
+    forceMousePassthrough: true,
+  } as never);
+
+  assert.ok(calls.includes('show-inactive'));
+  assert.ok(!calls.includes('always-on-top:false'));
+  assert.ok(!calls.includes('move-top'));
+  assert.ok(calls.includes('sync-windows-z-order'));
+});
+
+test('forced mouse passthrough drops macOS tracked overlay below higher-priority windows', () => {
+  const { window, calls } = createMainWindowRecorder();
+  const tracker: WindowTrackerStub = {
+    isTracking: () => true,
+    getGeometry: () => ({ x: 0, y: 0, width: 1280, height: 720 }),
+  };
+
+  updateVisibleOverlayVisibility({
+    visibleOverlayVisible: true,
+    mainWindow: window as never,
+    windowTracker: tracker as never,
+    trackerNotReadyWarningShown: false,
+    setTrackerNotReadyWarningShown: () => {},
+    updateVisibleOverlayBounds: () => {
+      calls.push('update-bounds');
+    },
+    ensureOverlayWindowLevel: () => {
+      calls.push('ensure-level');
+    },
+    syncPrimaryOverlayWindowLayer: () => {
+      calls.push('sync-layer');
+    },
+    enforceOverlayLayerOrder: () => {
+      calls.push('enforce-order');
+    },
+    syncOverlayShortcuts: () => {
+      calls.push('sync-shortcuts');
+    },
+    isMacOSPlatform: true,
+    isWindowsPlatform: false,
+    forceMousePassthrough: true,
+  } as never);
+
+  assert.ok(calls.includes('mouse-ignore:true:forward'));
+  assert.ok(calls.includes('always-on-top:false'));
+  assert.ok(!calls.includes('ensure-level'));
+  assert.ok(!calls.includes('enforce-order'));
+});
+
+test('tracked Windows overlay rebinds without hiding when tracker focus changes', () => {
+  const { window, calls } = createMainWindowRecorder();
+  let focused = true;
+  const tracker: WindowTrackerStub = {
+    isTracking: () => true,
+    getGeometry: () => ({ x: 0, y: 0, width: 1280, height: 720 }),
+    isTargetWindowFocused: () => focused,
+  };
+
+  updateVisibleOverlayVisibility({
+    visibleOverlayVisible: true,
+    mainWindow: window as never,
+    windowTracker: tracker as never,
+    trackerNotReadyWarningShown: false,
+    setTrackerNotReadyWarningShown: () => {},
+    updateVisibleOverlayBounds: () => {
+      calls.push('update-bounds');
+    },
+    ensureOverlayWindowLevel: () => {
+      calls.push('ensure-level');
+    },
+    syncWindowsOverlayToMpvZOrder: () => {
+      calls.push('sync-windows-z-order');
+    },
+    syncPrimaryOverlayWindowLayer: () => {
+      calls.push('sync-layer');
+    },
+    enforceOverlayLayerOrder: () => {
+      calls.push('enforce-order');
+    },
+    syncOverlayShortcuts: () => {
+      calls.push('sync-shortcuts');
+    },
+    isMacOSPlatform: false,
+    isWindowsPlatform: true,
+  } as never);
+
+  calls.length = 0;
+  focused = false;
+
+  updateVisibleOverlayVisibility({
+    visibleOverlayVisible: true,
+    mainWindow: window as never,
+    windowTracker: tracker as never,
+    trackerNotReadyWarningShown: false,
+    setTrackerNotReadyWarningShown: () => {},
+    updateVisibleOverlayBounds: () => {
+      calls.push('update-bounds');
+    },
+    ensureOverlayWindowLevel: () => {
+      calls.push('ensure-level');
+    },
+    syncWindowsOverlayToMpvZOrder: () => {
+      calls.push('sync-windows-z-order');
+    },
+    syncPrimaryOverlayWindowLayer: () => {
+      calls.push('sync-layer');
+    },
+    enforceOverlayLayerOrder: () => {
+      calls.push('enforce-order');
+    },
+    syncOverlayShortcuts: () => {
+      calls.push('sync-shortcuts');
+    },
+    isMacOSPlatform: false,
+    isWindowsPlatform: true,
+  } as never);
+
+  assert.ok(!calls.includes('always-on-top:false'));
+  assert.ok(!calls.includes('move-top'));
+  assert.ok(calls.includes('mouse-ignore:true:forward'));
+  assert.ok(calls.includes('sync-windows-z-order'));
+  assert.ok(!calls.includes('ensure-level'));
+  assert.ok(!calls.includes('enforce-order'));
+  assert.ok(!calls.includes('show'));
+});
+
+test('tracked Windows overlay stays interactive while the overlay window itself is focused', () => {
+  const { window, calls, setFocused } = createMainWindowRecorder();
+  const tracker: WindowTrackerStub = {
+    isTracking: () => true,
+    getGeometry: () => ({ x: 0, y: 0, width: 1280, height: 720 }),
+    isTargetWindowFocused: () => false,
+  };
+
+  updateVisibleOverlayVisibility({
+    visibleOverlayVisible: true,
+    mainWindow: window as never,
+    windowTracker: tracker as never,
+    trackerNotReadyWarningShown: false,
+    setTrackerNotReadyWarningShown: () => {},
+    updateVisibleOverlayBounds: () => {
+      calls.push('update-bounds');
+    },
+    ensureOverlayWindowLevel: () => {
+      calls.push('ensure-level');
+    },
+    syncWindowsOverlayToMpvZOrder: () => {
+      calls.push('sync-windows-z-order');
+    },
+    syncPrimaryOverlayWindowLayer: () => {
+      calls.push('sync-layer');
+    },
+    enforceOverlayLayerOrder: () => {
+      calls.push('enforce-order');
+    },
+    syncOverlayShortcuts: () => {
+      calls.push('sync-shortcuts');
+    },
+    isMacOSPlatform: false,
+    isWindowsPlatform: true,
+  } as never);
+
+  calls.length = 0;
+  setFocused(true);
+
+  updateVisibleOverlayVisibility({
+    visibleOverlayVisible: true,
+    mainWindow: window as never,
+    windowTracker: tracker as never,
+    trackerNotReadyWarningShown: false,
+    setTrackerNotReadyWarningShown: () => {},
+    updateVisibleOverlayBounds: () => {
+      calls.push('update-bounds');
+    },
+    ensureOverlayWindowLevel: () => {
+      calls.push('ensure-level');
+    },
+    syncWindowsOverlayToMpvZOrder: () => {
+      calls.push('sync-windows-z-order');
+    },
+    syncPrimaryOverlayWindowLayer: () => {
+      calls.push('sync-layer');
+    },
+    enforceOverlayLayerOrder: () => {
+      calls.push('enforce-order');
+    },
+    syncOverlayShortcuts: () => {
+      calls.push('sync-shortcuts');
+    },
+    isMacOSPlatform: false,
+    isWindowsPlatform: true,
+  } as never);
+
+  assert.ok(calls.includes('mouse-ignore:false:plain'));
+  assert.ok(calls.includes('sync-windows-z-order'));
+  assert.ok(!calls.includes('move-top'));
+  assert.ok(!calls.includes('ensure-level'));
+  assert.ok(!calls.includes('enforce-order'));
+});
+
+test('tracked Windows overlay binds above mpv even when tracker focus lags', () => {
+  const { window, calls } = createMainWindowRecorder();
+  const tracker: WindowTrackerStub = {
+    isTracking: () => true,
+    getGeometry: () => ({ x: 0, y: 0, width: 1280, height: 720 }),
+    isTargetWindowFocused: () => false,
+  };
+
+  updateVisibleOverlayVisibility({
+    visibleOverlayVisible: true,
+    mainWindow: window as never,
+    windowTracker: tracker as never,
+    trackerNotReadyWarningShown: false,
+    setTrackerNotReadyWarningShown: () => {},
+    updateVisibleOverlayBounds: () => {
+      calls.push('update-bounds');
+    },
+    ensureOverlayWindowLevel: () => {
+      calls.push('ensure-level');
+    },
+    syncWindowsOverlayToMpvZOrder: () => {
+      calls.push('sync-windows-z-order');
+    },
+    syncPrimaryOverlayWindowLayer: () => {
+      calls.push('sync-layer');
+    },
+    enforceOverlayLayerOrder: () => {
+      calls.push('enforce-order');
+    },
+    syncOverlayShortcuts: () => {
+      calls.push('sync-shortcuts');
+    },
+    isMacOSPlatform: false,
+    isWindowsPlatform: true,
+  } as never);
+
+  assert.ok(!calls.includes('always-on-top:false'));
+  assert.ok(!calls.includes('move-top'));
+  assert.ok(calls.includes('mouse-ignore:true:forward'));
+  assert.ok(calls.includes('sync-windows-z-order'));
+  assert.ok(!calls.includes('ensure-level'));
 });

 test('visible overlay stays hidden while a modal window is active', () => {
@@ -487,6 +858,157 @@ test('Windows keeps visible overlay hidden while tracker is not ready', () => {
  assert.ok(!calls.includes('update-bounds'));
 });

+test('Windows preserves visible overlay and rebinds to mpv while tracker transiently loses a non-minimized window', () => {
+  const { window, calls } = createMainWindowRecorder();
+  let tracking = true;
+  const tracker: WindowTrackerStub = {
+    isTracking: () => tracking,
+    getGeometry: () => ({ x: 0, y: 0, width: 1280, height: 720 }),
+    isTargetWindowFocused: () => false,
+    isTargetWindowMinimized: () => false,
+  };
+
+  updateVisibleOverlayVisibility({
+    visibleOverlayVisible: true,
+    mainWindow: window as never,
+    windowTracker: tracker as never,
+    trackerNotReadyWarningShown: false,
+    setTrackerNotReadyWarningShown: () => {},
+    updateVisibleOverlayBounds: () => {
+      calls.push('update-bounds');
+    },
+    ensureOverlayWindowLevel: () => {
+      calls.push('ensure-level');
+    },
+    syncWindowsOverlayToMpvZOrder: () => {
+      calls.push('sync-windows-z-order');
+    },
+    syncPrimaryOverlayWindowLayer: () => {
+      calls.push('sync-layer');
+    },
+    enforceOverlayLayerOrder: () => {
+      calls.push('enforce-order');
+    },
+    syncOverlayShortcuts: () => {
+      calls.push('sync-shortcuts');
+    },
+    isMacOSPlatform: false,
+    isWindowsPlatform: true,
+  } as never);
+
+  calls.length = 0;
+  tracking = false;
+
+  updateVisibleOverlayVisibility({
+    visibleOverlayVisible: true,
+    mainWindow: window as never,
+    windowTracker: tracker as never,
+    trackerNotReadyWarningShown: false,
+    setTrackerNotReadyWarningShown: () => {},
+    updateVisibleOverlayBounds: () => {
+      calls.push('update-bounds');
+    },
+    ensureOverlayWindowLevel: () => {
+      calls.push('ensure-level');
+    },
+    syncWindowsOverlayToMpvZOrder: () => {
+      calls.push('sync-windows-z-order');
+    },
+    syncPrimaryOverlayWindowLayer: () => {
+      calls.push('sync-layer');
+    },
+    enforceOverlayLayerOrder: () => {
+      calls.push('enforce-order');
+    },
+    syncOverlayShortcuts: () => {
+      calls.push('sync-shortcuts');
+    },
+    isMacOSPlatform: false,
+    isWindowsPlatform: true,
+  } as never);
+
+  assert.ok(!calls.includes('hide'));
+  assert.ok(!calls.includes('show'));
+  assert.ok(!calls.includes('always-on-top:false'));
+  assert.ok(!calls.includes('move-top'));
+  assert.ok(calls.includes('mouse-ignore:true:forward'));
+  assert.ok(calls.includes('sync-windows-z-order'));
+  assert.ok(!calls.includes('ensure-level'));
+  assert.ok(calls.includes('sync-shortcuts'));
+});
+
+test('Windows hides the visible overlay when the tracked window is minimized', () => {
+  const { window, calls } = createMainWindowRecorder();
+  let tracking = true;
+  const tracker: WindowTrackerStub = {
+    isTracking: () => tracking,
+    getGeometry: () => (tracking ? { x: 0, y: 0, width: 1280, height: 720 } : null),
+    isTargetWindowMinimized: () => !tracking,
+  };
+
+  updateVisibleOverlayVisibility({
+    visibleOverlayVisible: true,
+    mainWindow: window as never,
+    windowTracker: tracker as never,
+    trackerNotReadyWarningShown: false,
+    setTrackerNotReadyWarningShown: () => {},
+    updateVisibleOverlayBounds: () => {
+      calls.push('update-bounds');
+    },
+    ensureOverlayWindowLevel: () => {
+      calls.push('ensure-level');
+    },
+    syncWindowsOverlayToMpvZOrder: () => {
+      calls.push('sync-windows-z-order');
+    },
+    syncPrimaryOverlayWindowLayer: () => {
+      calls.push('sync-layer');
+    },
+    enforceOverlayLayerOrder: () => {
+      calls.push('enforce-order');
+    },
+    syncOverlayShortcuts: () => {
+      calls.push('sync-shortcuts');
+    },
+    isMacOSPlatform: false,
+    isWindowsPlatform: true,
+  } as never);
+
+  calls.length = 0;
+  tracking = false;
+
+  updateVisibleOverlayVisibility({
+    visibleOverlayVisible: true,
+    mainWindow: window as never,
+    windowTracker: tracker as never,
+    trackerNotReadyWarningShown: false,
+    setTrackerNotReadyWarningShown: () => {},
+    updateVisibleOverlayBounds: () => {
+      calls.push('update-bounds');
+    },
+    ensureOverlayWindowLevel: () => {
+      calls.push('ensure-level');
+    },
+    syncWindowsOverlayToMpvZOrder: () => {
+      calls.push('sync-windows-z-order');
+    },
+    syncPrimaryOverlayWindowLayer: () => {
+      calls.push('sync-layer');
+    },
+    enforceOverlayLayerOrder: () => {
+      calls.push('enforce-order');
+    },
+    syncOverlayShortcuts: () => {
+      calls.push('sync-shortcuts');
+    },
+    isMacOSPlatform: false,
+    isWindowsPlatform: true,
+  } as never);
+
+  assert.ok(calls.includes('hide'));
+  assert.ok(!calls.includes('sync-windows-z-order'));
+});
+
 test('macOS keeps visible overlay hidden while tracker is not initialized yet', () => {
  const { window, calls } = createMainWindowRecorder();
  let trackerWarning = false;
--- a/src/core/services/overlay-visibility.ts
+++ b/src/core/services/overlay-visibility.ts
@@ -2,16 +2,63 @@ import type { BrowserWindow } from 'electron';
 import { BaseWindowTracker } from '../../window-trackers';
 import { WindowGeometry } from '../../types';

+const WINDOWS_OVERLAY_REVEAL_DELAY_MS = 48;
+const pendingWindowsOverlayRevealTimeoutByWindow = new WeakMap<
+  BrowserWindow,
+  ReturnType<typeof setTimeout>
+>();
+const OVERLAY_WINDOW_CONTENT_READY_FLAG = '__subminerOverlayContentReady';
+
+function setOverlayWindowOpacity(window: BrowserWindow, opacity: number): void {
+  const opacityCapableWindow = window as BrowserWindow & {
+    setOpacity?: (opacity: number) => void;
+  };
+  opacityCapableWindow.setOpacity?.(opacity);
+}
+
+function clearPendingWindowsOverlayReveal(window: BrowserWindow): void {
+  const pendingTimeout = pendingWindowsOverlayRevealTimeoutByWindow.get(window);
+  if (!pendingTimeout) {
+    return;
+  }
+  clearTimeout(pendingTimeout);
+  pendingWindowsOverlayRevealTimeoutByWindow.delete(window);
+}
+
+function scheduleWindowsOverlayReveal(window: BrowserWindow): void {
+  clearPendingWindowsOverlayReveal(window);
+  const timeout = setTimeout(() => {
+    pendingWindowsOverlayRevealTimeoutByWindow.delete(window);
+    if (window.isDestroyed() || !window.isVisible()) {
+      return;
+    }
+    setOverlayWindowOpacity(window, 1);
+  }, WINDOWS_OVERLAY_REVEAL_DELAY_MS);
+  pendingWindowsOverlayRevealTimeoutByWindow.set(window, timeout);
+}
+
+function isOverlayWindowContentReady(window: BrowserWindow): boolean {
+  return (
+    (window as BrowserWindow & { [OVERLAY_WINDOW_CONTENT_READY_FLAG]?: boolean })[
+      OVERLAY_WINDOW_CONTENT_READY_FLAG
+    ] === true
+  );
+}
+
 export function updateVisibleOverlayVisibility(args: {
  visibleOverlayVisible: boolean;
  modalActive?: boolean;
  forceMousePassthrough?: boolean;
  mainWindow: BrowserWindow | null;
  windowTracker: BaseWindowTracker | null;
+  lastKnownWindowsForegroundProcessName?: string | null;
+  windowsOverlayProcessName?: string | null;
+  windowsFocusHandoffGraceActive?: boolean;
  trackerNotReadyWarningShown: boolean;
  setTrackerNotReadyWarningShown: (shown: boolean) => void;
  updateVisibleOverlayBounds: (geometry: WindowGeometry) => void;
  ensureOverlayWindowLevel: (window: BrowserWindow) => void;
+  syncWindowsOverlayToMpvZOrder?: (window: BrowserWindow) => void;
  syncPrimaryOverlayWindowLayer: (layer: 'visible') => void;
  enforceOverlayLayerOrder: () => void;
  syncOverlayShortcuts: () => void;
@@ -30,6 +77,10 @@ export function updateVisibleOverlayVisibility(args: {
  const mainWindow = args.mainWindow;

  if (args.modalActive) {
+    if (args.isWindowsPlatform) {
+      clearPendingWindowsOverlayReveal(mainWindow);
+      setOverlayWindowOpacity(mainWindow, 0);
+    }
    mainWindow.hide();
    args.syncOverlayShortcuts();
    return;
@@ -39,19 +90,86 @@ export function updateVisibleOverlayVisibility(args: {
    const forceMousePassthrough = args.forceMousePassthrough === true;
    const shouldDefaultToPassthrough =
      args.isMacOSPlatform || args.isWindowsPlatform || forceMousePassthrough;
+    const isVisibleOverlayFocused =
+      typeof mainWindow.isFocused === 'function' && mainWindow.isFocused();
+    const windowsForegroundProcessName =
+      args.lastKnownWindowsForegroundProcessName?.trim().toLowerCase() ?? null;
+    const windowsOverlayProcessName = args.windowsOverlayProcessName?.trim().toLowerCase() ?? null;
+    const hasWindowsForegroundProcessSignal =
+      args.isWindowsPlatform && windowsForegroundProcessName !== null;
+    const isTrackedWindowsTargetFocused = args.windowTracker?.isTargetWindowFocused?.() ?? true;
+    const isTrackedWindowsTargetMinimized =
+      args.isWindowsPlatform &&
+      typeof args.windowTracker?.isTargetWindowMinimized === 'function' &&
+      args.windowTracker.isTargetWindowMinimized();
+    const shouldPreserveWindowsOverlayDuringFocusHandoff =
+      args.isWindowsPlatform &&
+      args.windowsFocusHandoffGraceActive === true &&
+      !!args.windowTracker &&
+      (!hasWindowsForegroundProcessSignal ||
+        windowsForegroundProcessName === 'mpv' ||
+        (windowsOverlayProcessName !== null &&
+          windowsForegroundProcessName === windowsOverlayProcessName)) &&
+      !isTrackedWindowsTargetMinimized &&
+      (args.windowTracker.isTracking() || args.windowTracker.getGeometry() !== null);
+    const shouldIgnoreMouseEvents =
+      forceMousePassthrough || (shouldDefaultToPassthrough && !isVisibleOverlayFocused);
+    const shouldBindTrackedWindowsOverlay = args.isWindowsPlatform && !!args.windowTracker;
+    const shouldKeepTrackedWindowsOverlayTopmost =
+      !args.isWindowsPlatform ||
+      !args.windowTracker ||
+      isVisibleOverlayFocused ||
+      isTrackedWindowsTargetFocused ||
+      shouldPreserveWindowsOverlayDuringFocusHandoff ||
+      (hasWindowsForegroundProcessSignal && windowsForegroundProcessName === 'mpv');
    const wasVisible = mainWindow.isVisible();

-    if (!wasVisible || forceMousePassthrough) {
-      if (shouldDefaultToPassthrough) {
+    if (shouldIgnoreMouseEvents) {
+      mainWindow.setIgnoreMouseEvents(true, { forward: true });
+    } else {
+      mainWindow.setIgnoreMouseEvents(false);
+    }
+
+    if (shouldBindTrackedWindowsOverlay) {
+      // On Windows, z-order is enforced by the OS via the owner window mechanism
+      // (SetWindowLongPtr GWLP_HWNDPARENT). The overlay is always above mpv
+      // without any manual z-order management.
+    } else if (!forceMousePassthrough) {
+      args.ensureOverlayWindowLevel(mainWindow);
+    } else {
+      mainWindow.setAlwaysOnTop(false);
+    }
+    if (!wasVisible) {
+      const hasWebContents =
+        typeof (mainWindow as unknown as { webContents?: unknown }).webContents === 'object';
+      if (
+        args.isWindowsPlatform &&
+        hasWebContents &&
+        !isOverlayWindowContentReady(mainWindow as unknown as import('electron').BrowserWindow)
+      ) {
+        // skip — ready-to-show hasn't fired yet; the onWindowContentReady
+        // callback will trigger another visibility update when the renderer
+        // has painted its first frame.
+      } else if (args.isWindowsPlatform && shouldIgnoreMouseEvents) {
+        setOverlayWindowOpacity(mainWindow, 0);
+        mainWindow.showInactive();
        mainWindow.setIgnoreMouseEvents(true, { forward: true });
+        scheduleWindowsOverlayReveal(mainWindow);
      } else {
-        mainWindow.setIgnoreMouseEvents(false);
+        if (args.isWindowsPlatform) {
+          setOverlayWindowOpacity(mainWindow, 0);
+        }
+        mainWindow.show();
+        if (args.isWindowsPlatform) {
+          scheduleWindowsOverlayReveal(mainWindow);
+        }
      }
    }
-    args.ensureOverlayWindowLevel(mainWindow);
-    if (!wasVisible) {
-      mainWindow.show();
+
+    if (shouldBindTrackedWindowsOverlay) {
+      args.syncWindowsOverlayToMpvZOrder?.(mainWindow);
    }
+
    if (!args.isWindowsPlatform && !args.isMacOSPlatform && !forceMousePassthrough) {
      mainWindow.focus();
    }
@@ -71,6 +189,10 @@ export function updateVisibleOverlayVisibility(args: {
  if (!args.visibleOverlayVisible) {
    args.setTrackerNotReadyWarningShown(false);
    args.resetOverlayLoadingOsdSuppression?.();
+    if (args.isWindowsPlatform) {
+      clearPendingWindowsOverlayReveal(mainWindow);
+      setOverlayWindowOpacity(mainWindow, 0);
+    }
    mainWindow.hide();
    args.syncOverlayShortcuts();
    return;
@@ -84,7 +206,9 @@ export function updateVisibleOverlayVisibility(args: {
    }
    args.syncPrimaryOverlayWindowLayer('visible');
    showPassiveVisibleOverlay();
-    args.enforceOverlayLayerOrder();
+    if (!args.forceMousePassthrough && !args.isWindowsPlatform) {
+      args.enforceOverlayLayerOrder();
+    }
    args.syncOverlayShortcuts();
    return;
  }
@@ -95,6 +219,10 @@ export function updateVisibleOverlayVisibility(args: {
        args.setTrackerNotReadyWarningShown(true);
        maybeShowOverlayLoadingOsd();
      }
+      if (args.isWindowsPlatform) {
+        clearPendingWindowsOverlayReveal(mainWindow);
+        setOverlayWindowOpacity(mainWindow, 0);
+      }
      mainWindow.hide();
      args.syncOverlayShortcuts();
      return;
@@ -107,11 +235,32 @@ export function updateVisibleOverlayVisibility(args: {
    return;
  }

+  if (
+    args.isWindowsPlatform &&
+    typeof args.windowTracker.isTargetWindowMinimized === 'function' &&
+    !args.windowTracker.isTargetWindowMinimized() &&
+    (mainWindow.isVisible() || args.windowTracker.getGeometry() !== null)
+  ) {
+    args.setTrackerNotReadyWarningShown(false);
+    const geometry = args.windowTracker.getGeometry();
+    if (geometry) {
+      args.updateVisibleOverlayBounds(geometry);
+    }
+    args.syncPrimaryOverlayWindowLayer('visible');
+    showPassiveVisibleOverlay();
+    args.syncOverlayShortcuts();
+    return;
+  }
+
  if (!args.trackerNotReadyWarningShown) {
    args.setTrackerNotReadyWarningShown(true);
    maybeShowOverlayLoadingOsd();
  }

+  if (args.isWindowsPlatform) {
+    clearPendingWindowsOverlayReveal(mainWindow);
+    setOverlayWindowOpacity(mainWindow, 0);
+  }
  mainWindow.hide();
  args.syncOverlayShortcuts();
 }
--- a/src/core/services/overlay-window-config.test.ts
+++ b/src/core/services/overlay-window-config.test.ts
@@ -8,7 +8,32 @@ test('overlay window config explicitly disables renderer sandbox for preload com
    yomitanSession: null,
  });

+  assert.equal(options.backgroundColor, '#00000000');
  assert.equal(options.webPreferences?.sandbox, false);
+  assert.equal(options.webPreferences?.backgroundThrottling, false);
+});
+
+test('Windows visible overlay window config does not start as always-on-top', () => {
+  const originalPlatform = process.platform;
+
+  Object.defineProperty(process, 'platform', {
+    configurable: true,
+    value: 'win32',
+  });
+
+  try {
+    const options = buildOverlayWindowOptions('visible', {
+      isDev: false,
+      yomitanSession: null,
+    });
+
+    assert.equal(options.alwaysOnTop, false);
+  } finally {
+    Object.defineProperty(process, 'platform', {
+      configurable: true,
+      value: originalPlatform,
+    });
+  }
 });

 test('overlay window config uses the provided Yomitan session when available', () => {
--- a/src/core/services/overlay-window-input.ts
+++ b/src/core/services/overlay-window-input.ts
@@ -66,7 +66,14 @@ export function handleOverlayWindowBlurred(options: {
  isOverlayVisible: (kind: OverlayWindowKind) => boolean;
  ensureOverlayWindowLevel: () => void;
  moveWindowTop: () => void;
+  onWindowsVisibleOverlayBlur?: () => void;
+  platform?: NodeJS.Platform;
 }): boolean {
+  if ((options.platform ?? process.platform) === 'win32' && options.kind === 'visible') {
+    options.onWindowsVisibleOverlayBlur?.();
+    return false;
+  }
+
  if (options.kind === 'visible' && !options.isOverlayVisible(options.kind)) {
    return false;
  }
--- a/src/core/services/overlay-window-options.ts
+++ b/src/core/services/overlay-window-options.ts
@@ -10,6 +10,7 @@ export function buildOverlayWindowOptions(
  },
 ): BrowserWindowConstructorOptions {
  const showNativeDebugFrame = process.platform === 'win32' && options.isDev;
+  const shouldStartAlwaysOnTop = !(process.platform === 'win32' && kind === 'visible');

  return {
    show: false,
@@ -18,8 +19,9 @@ export function buildOverlayWindowOptions(
    x: 0,
    y: 0,
    transparent: true,
+    backgroundColor: '#00000000',
    frame: false,
-    alwaysOnTop: true,
+    alwaysOnTop: shouldStartAlwaysOnTop,
    skipTaskbar: true,
    resizable: false,
    hasShadow: false,
@@ -31,6 +33,7 @@ export function buildOverlayWindowOptions(
      contextIsolation: true,
      nodeIntegration: false,
      sandbox: false,
+      backgroundThrottling: false,
      webSecurity: true,
      session: options.yomitanSession ?? undefined,
      additionalArguments: [`--overlay-layer=${kind}`],
--- a/src/core/services/overlay-window.test.ts
+++ b/src/core/services/overlay-window.test.ts
@@ -103,6 +103,49 @@ test('handleOverlayWindowBlurred skips visible overlay restacking after manual h
  assert.deepEqual(calls, []);
 });

+test('handleOverlayWindowBlurred skips Windows visible overlay restacking after focus loss', () => {
+  const calls: string[] = [];
+
+  const handled = handleOverlayWindowBlurred({
+    kind: 'visible',
+    windowVisible: true,
+    isOverlayVisible: () => true,
+    ensureOverlayWindowLevel: () => {
+      calls.push('ensure-level');
+    },
+    moveWindowTop: () => {
+      calls.push('move-top');
+    },
+    platform: 'win32',
+  });
+
+  assert.equal(handled, false);
+  assert.deepEqual(calls, []);
+});
+
+test('handleOverlayWindowBlurred notifies Windows visible overlay blur callback without restacking', () => {
+  const calls: string[] = [];
+
+  const handled = handleOverlayWindowBlurred({
+    kind: 'visible',
+    windowVisible: true,
+    isOverlayVisible: () => true,
+    ensureOverlayWindowLevel: () => {
+      calls.push('ensure-level');
+    },
+    moveWindowTop: () => {
+      calls.push('move-top');
+    },
+    onWindowsVisibleOverlayBlur: () => {
+      calls.push('windows-visible-blur');
+    },
+    platform: 'win32',
+  });
+
+  assert.equal(handled, false);
+  assert.deepEqual(calls, ['windows-visible-blur']);
+});
+
 test('handleOverlayWindowBlurred preserves active visible/modal window stacking', () => {
  const calls: string[] = [];

@@ -117,6 +160,7 @@ test('handleOverlayWindowBlurred preserves active visible/modal window stacking'
      moveWindowTop: () => {
        calls.push('move-visible');
      },
+      platform: 'linux',
    }),
    true,
  );
--- a/src/core/services/overlay-window.ts
+++ b/src/core/services/overlay-window.ts
@@ -13,6 +13,17 @@ import { normalizeOverlayWindowBoundsForPlatform } from './overlay-window-bounds

 const logger = createLogger('main:overlay-window');
 const overlayWindowLayerByInstance = new WeakMap<BrowserWindow, OverlayWindowKind>();
+const overlayWindowContentReady = new WeakSet<BrowserWindow>();
+const OVERLAY_WINDOW_CONTENT_READY_FLAG = '__subminerOverlayContentReady';
+
+export function isOverlayWindowContentReady(window: BrowserWindow): boolean {
+  return (
+    overlayWindowContentReady.has(window) ||
+    (window as BrowserWindow & { [OVERLAY_WINDOW_CONTENT_READY_FLAG]?: boolean })[
+      OVERLAY_WINDOW_CONTENT_READY_FLAG
+    ] === true
+  );
+}

 function getOverlayWindowHtmlPath(): string {
  return path.join(__dirname, '..', '..', 'renderer', 'index.html');
@@ -76,13 +87,17 @@ export function createOverlayWindow(
    isOverlayVisible: (kind: OverlayWindowKind) => boolean;
    tryHandleOverlayShortcutLocalFallback: (input: Electron.Input) => boolean;
    forwardTabToMpv: () => void;
+    onVisibleWindowBlurred?: () => void;
+    onWindowContentReady?: () => void;
    onWindowClosed: (kind: OverlayWindowKind) => void;
    yomitanSession?: Session | null;
  },
 ): BrowserWindow {
  const window = new BrowserWindow(buildOverlayWindowOptions(kind, options));

-  options.ensureOverlayWindowLevel(window);
+  if (!(process.platform === 'win32' && kind === 'visible')) {
+    options.ensureOverlayWindowLevel(window);
+  }
  loadOverlayWindowLayer(window, kind);

  window.webContents.on('did-fail-load', (_event, errorCode, errorDescription, validatedURL) => {
@@ -93,6 +108,14 @@ export function createOverlayWindow(
    options.onRuntimeOptionsChanged();
  });

+  window.once('ready-to-show', () => {
+    overlayWindowContentReady.add(window);
+    (window as BrowserWindow & { [OVERLAY_WINDOW_CONTENT_READY_FLAG]?: boolean })[
+      OVERLAY_WINDOW_CONTENT_READY_FLAG
+    ] = true;
+    options.onWindowContentReady?.();
+  });
+
  if (kind === 'visible') {
    window.webContents.on('devtools-opened', () => {
      options.setOverlayDebugVisualizationEnabled(true);
@@ -136,6 +159,8 @@ export function createOverlayWindow(
      moveWindowTop: () => {
        window.moveTop();
      },
+      onWindowsVisibleOverlayBlur:
+        kind === 'visible' ? () => options.onVisibleWindowBlurred?.() : undefined,
    });
  });