diff --git a/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/PlatformRoot.vue b/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/PlatformRoot.vue
index 5b689dd13..fd0975ae3 100644
--- a/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/PlatformRoot.vue
+++ b/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/PlatformRoot.vue
@@ -1,6 +1,9 @@
 <script setup lang="ts">
-import { computed } from 'vue'
+import type { Ref } from 'vue'
 
+import { computed, provide, readonly, ref } from 'vue'
+
+import { injectPlatformLayout } from './constants'
 import { Appearance, Dock, MenuBar } from './ui'
 
 const props = withDefaults(defineProps<{
@@ -21,10 +24,19 @@ const aspectRatio = computed(() => {
 
   return props.aspectRatio.split(':').map(Number).reduce((a, b) => a / b)
 })
+
+const platformRoot = ref<HTMLElement | null>(null)
+const dockRoot = ref<HTMLElement | null>(null)
+
+provide(injectPlatformLayout, {
+  dock: dockRoot,
+  root: readonly(platformRoot) as Readonly<Ref<HTMLElement | null>>,
+})
 </script>
 
 <template>
   <div
+    ref="platformRoot"
     :class="[
       'relative overflow-hidden',
       'font-macos',
diff --git a/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/constants.ts b/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/constants.ts
new file mode 100644
index 000000000..191165820
--- /dev/null
+++ b/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/constants.ts
@@ -0,0 +1,8 @@
+import type { InjectionKey, Ref } from 'vue'
+
+export interface PlatformLayoutContext {
+  dock: Ref<HTMLElement | null>
+  root: Readonly<Ref<HTMLElement | null>>
+}
+
+export const injectPlatformLayout: InjectionKey<PlatformLayoutContext> = Symbol('vishot:platforms:macos-26:layout')
diff --git a/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/containers/window/WindowRoot.vue b/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/containers/window/WindowRoot.vue
index b997a755a..93bc37daa 100644
--- a/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/containers/window/WindowRoot.vue
+++ b/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/containers/window/WindowRoot.vue
@@ -1,4 +1,11 @@
 <script setup lang="ts">
+import type { CSSProperties } from 'vue'
+
+import { inject, nextTick, onBeforeUnmount, onMounted, ref, shallowRef, watch } from 'vue'
+
+import { injectPlatformLayout } from '../../constants'
+import { computeElementAnchorStyle, createContainerAnchorStyle, createWorkAreaRect } from './window-anchor'
+
 const props = withDefaults(defineProps<{
   title?: string
   focus?: boolean
@@ -6,24 +13,146 @@ const props = withDefaults(defineProps<{
   transparent?: boolean
   titleBarStyle?: 'default' | 'hidden' | 'hiddenInset' | 'customButtonsOnHover'
   hasShadow?: boolean
-  alignTo?: 'bottom-left' | 'bottom-right' | 'top-left' | 'top-right' | 'center'
+  anchorTo?: 'bottom-left' | 'bottom-right' | 'top-left' | 'top-right' | 'center'
+  anchorEl?: HTMLElement | SVGElement | null
+  anchorBounds?: 'platform' | 'workarea'
 }>(), {
+  anchorBounds: 'platform',
   focus: true,
   frame: true,
   transparent: false,
   titleBarStyle: 'default',
   hasShadow: true,
 })
+
+const platformLayout = inject(injectPlatformLayout, null)
+const windowRoot = ref<HTMLElement | null>(null)
+const anchorStyle = shallowRef<CSSProperties | undefined>()
+
+let resizeObserver: ResizeObserver | null = null
+let animationFrameId: number | null = null
+
+function cancelPendingAnchorUpdate() {
+  if (animationFrameId !== null) {
+    cancelAnimationFrame(animationFrameId)
+    animationFrameId = null
+  }
+}
+
+function updateAnchorStyle() {
+  if (!props.anchorTo) {
+    anchorStyle.value = undefined
+    return
+  }
+
+  const currentPlatformRoot = platformLayout?.root.value ?? null
+  const currentWindowRoot = windowRoot.value
+  const currentAnchorEl = props.anchorEl instanceof HTMLElement || props.anchorEl instanceof SVGElement
+    ? props.anchorEl
+    : null
+
+  // Element anchoring is the more specific mode: align this window to the
+  // measured target element inside the platform rather than to a platform edge.
+  if (currentAnchorEl && currentPlatformRoot && currentWindowRoot) {
+    anchorStyle.value = computeElementAnchorStyle({
+      anchor: props.anchorTo,
+      anchorRect: currentAnchorEl.getBoundingClientRect(),
+      platformRect: currentPlatformRoot.getBoundingClientRect(),
+      windowRect: currentWindowRoot.getBoundingClientRect(),
+    })
+    return
+  }
+
+  const platformRect = currentPlatformRoot?.getBoundingClientRect()
+  // When anchoring against the container, we can optionally shrink the usable
+  // bounds to the platform work area so windows avoid overlapping the dock.
+  const workAreaRect = platformRect
+    ? createWorkAreaRect({
+        dockRect: props.anchorBounds === 'workarea' ? platformLayout?.dock.value?.getBoundingClientRect() ?? null : null,
+        platformRect,
+      })
+    : undefined
+
+  anchorStyle.value = createContainerAnchorStyle(
+    props.anchorTo,
+    workAreaRect,
+    platformRect
+      ? {
+          width: platformRect.width,
+          height: platformRect.height,
+        }
+      : undefined,
+  )
+}
+
+function queueAnchorUpdate() {
+  cancelPendingAnchorUpdate()
+  // Layout reads happen on the next animation frame so repeated prop/observer
+  // changes collapse into one measurement pass.
+  animationFrameId = requestAnimationFrame(() => {
+    animationFrameId = null
+    updateAnchorStyle()
+  })
+}
+
+function refreshResizeObserver() {
+  resizeObserver?.disconnect()
+
+  if (typeof ResizeObserver === 'undefined') {
+    return
+  }
+
+  resizeObserver = new ResizeObserver(() => {
+    queueAnchorUpdate()
+  })
+
+  // The computed anchor can change when the platform, dock, window itself, or
+  // an explicit anchor element resizes, so all of them feed the same update path.
+  if (platformLayout?.root.value) {
+    resizeObserver.observe(platformLayout.root.value)
+  }
+
+  if (platformLayout?.dock.value) {
+    resizeObserver.observe(platformLayout.dock.value)
+  }
+
+  if (windowRoot.value) {
+    resizeObserver.observe(windowRoot.value)
+  }
+
+  if (props.anchorEl instanceof HTMLElement || props.anchorEl instanceof SVGElement) {
+    resizeObserver.observe(props.anchorEl)
+  }
+}
+
+onMounted(async () => {
+  await nextTick()
+  queueAnchorUpdate()
+  refreshResizeObserver()
+})
+
+watch(() => [props.anchorBounds, props.anchorTo, props.anchorEl], async () => {
+  await nextTick()
+  queueAnchorUpdate()
+  refreshResizeObserver()
+})
+
+onBeforeUnmount(() => {
+  cancelPendingAnchorUpdate()
+  resizeObserver?.disconnect()
+})
 </script>
 
 <template>
   <div
+    ref="windowRoot"
     :class="[
       'absolute',
       'flex flex-col',
       'rounded-2xl overflow-hidden',
       props.hasShadow ? 'shadow-xl' : '',
     ]"
+    :style="anchorStyle"
   >
     <div
       v-if="!!props.frame"
diff --git a/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/containers/window/window-anchor.test.ts b/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/containers/window/window-anchor.test.ts
new file mode 100644
index 000000000..4fa9e91b9
--- /dev/null
+++ b/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/containers/window/window-anchor.test.ts
@@ -0,0 +1,84 @@
+import { describe, expect, it } from 'vitest'
+
+import { computeElementAnchorStyle, createContainerAnchorStyle, createWorkAreaRect } from './window-anchor'
+
+describe('createContainerAnchorStyle', () => {
+  it('anchors a window to the platform top-right corner', () => {
+    expect(createContainerAnchorStyle('top-right')).toEqual({
+      right: '0px',
+      top: '0px',
+    })
+  })
+
+  it('centers a window in the platform', () => {
+    expect(createContainerAnchorStyle('center')).toEqual({
+      left: '50%',
+      top: '50%',
+      transform: 'translate(-50%, -50%)',
+    })
+  })
+
+  it('anchors a window to the usable area left of a vertical dock', () => {
+    expect(createContainerAnchorStyle('bottom-right', {
+      left: 0,
+      top: 0,
+      width: 1720,
+      height: 1080,
+    }, {
+      width: 1920,
+      height: 1080,
+    })).toEqual({
+      bottom: '0px',
+      right: '200px',
+    })
+  })
+})
+
+describe('createWorkAreaRect', () => {
+  it('shrinks the work area from the right edge for a vertical dock', () => {
+    expect(createWorkAreaRect({
+      platformRect: {
+        left: 0,
+        top: 0,
+        width: 1920,
+        height: 1080,
+      },
+      dockRect: {
+        left: 1720,
+        top: 240,
+        width: 160,
+        height: 600,
+      },
+    })).toEqual({
+      left: 0,
+      top: 0,
+      width: 1720,
+      height: 1080,
+    })
+  })
+})
+
+describe('computeElementAnchorStyle', () => {
+  it('anchors the same window corner to an element corner inside the platform', () => {
+    expect(computeElementAnchorStyle({
+      anchor: 'bottom-right',
+      anchorRect: {
+        left: 210,
+        top: 140,
+        width: 120,
+        height: 40,
+      },
+      platformRect: {
+        left: 100,
+        top: 50,
+      },
+      windowRect: {
+        width: 80,
+        height: 30,
+      },
+    })).toEqual({
+      left: '150px',
+      top: '100px',
+    })
+  })
+})
diff --git a/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/containers/window/window-anchor.ts b/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/containers/window/window-anchor.ts
new file mode 100644
index 000000000..834a22351
--- /dev/null
+++ b/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/containers/window/window-anchor.ts
@@ -0,0 +1,159 @@
+import type { CSSProperties } from 'vue'
+
+export type WindowAnchor = 'bottom-left' | 'bottom-right' | 'top-left' | 'top-right' | 'center'
+
+type RectPosition = Pick<DOMRect, 'left' | 'top'>
+type RectSize = Pick<DOMRect, 'width' | 'height'>
+type RectLike = RectPosition & RectSize
+type RelativeRect = RectLike
+
+function toRelativeRect(rect: RectLike, platformRect: RectPosition): RelativeRect {
+  // All anchor math is done in the platform's own coordinate system so callers
+  // can mix measured DOM rects with the logical scene layout consistently.
+  return {
+    left: rect.left - platformRect.left,
+    top: rect.top - platformRect.top,
+    width: rect.width,
+    height: rect.height,
+  }
+}
+
+function resolveAnchorPoint(rect: RectLike, anchor: WindowAnchor) {
+  switch (anchor) {
+    case 'top-left':
+      return { x: rect.left, y: rect.top }
+    case 'top-right':
+      return { x: rect.left + rect.width, y: rect.top }
+    case 'bottom-left':
+      return { x: rect.left, y: rect.top + rect.height }
+    case 'bottom-right':
+      return { x: rect.left + rect.width, y: rect.top + rect.height }
+    case 'center':
+      return { x: rect.left + rect.width / 2, y: rect.top + rect.height / 2 }
+  }
+}
+
+export function createContainerAnchorStyle(
+  anchor: WindowAnchor,
+  boundsRect?: RelativeRect,
+  platformSize?: RectSize,
+): CSSProperties {
+  // `boundsRect` describes the usable anchoring area inside the platform. When
+  // it is omitted we anchor against the full platform origin, matching the
+  // original behavior before dock-aware work areas existed.
+  const left = boundsRect?.left ?? 0
+  const top = boundsRect?.top ?? 0
+  const right = boundsRect && platformSize
+    ? platformSize.width - (boundsRect.left + boundsRect.width)
+    : 0
+  const bottom = boundsRect && platformSize
+    ? platformSize.height - (boundsRect.top + boundsRect.height)
+    : 0
+
+  switch (anchor) {
+    case 'top-left':
+      return {
+        left: `${left}px`,
+        top: `${top}px`,
+      }
+    case 'top-right':
+      return {
+        right: `${right}px`,
+        top: `${top}px`,
+      }
+    case 'bottom-left':
+      return {
+        bottom: `${bottom}px`,
+        left: `${left}px`,
+      }
+    case 'bottom-right':
+      return {
+        bottom: `${bottom}px`,
+        right: `${right}px`,
+      }
+    case 'center':
+      return {
+        left: boundsRect && platformSize ? `${left + boundsRect.width / 2}px` : '50%',
+        top: boundsRect && platformSize ? `${top + boundsRect.height / 2}px` : '50%',
+        transform: 'translate(-50%, -50%)',
+      }
+  }
+}
+
+export function createWorkAreaRect(options: {
+  dockRect?: RectLike | null
+  platformRect: RectLike
+}): RelativeRect {
+  if (!options.dockRect) {
+    return {
+      left: 0,
+      top: 0,
+      width: options.platformRect.width,
+      height: options.platformRect.height,
+    }
+  }
+
+  const dockRect = toRelativeRect(options.dockRect, options.platformRect)
+  // A tall dock behaves like a left/right sidebar; a wide dock behaves like a
+  // top/bottom shelf. We trim the usable work area from the nearest edge so
+  // bottom/right anchors can stay clear of the dock without hard-coded offsets.
+  const isVerticalDock = dockRect.height >= dockRect.width
+  const distances = {
+    bottom: options.platformRect.height - (dockRect.top + dockRect.height),
+    left: dockRect.left,
+    right: options.platformRect.width - (dockRect.left + dockRect.width),
+    top: dockRect.top,
+  }
+
+  const workArea = {
+    left: 0,
+    top: 0,
+    width: options.platformRect.width,
+    height: options.platformRect.height,
+  }
+
+  if (isVerticalDock) {
+    if (distances.left <= distances.right) {
+      const inset = dockRect.left + dockRect.width
+      workArea.left = inset
+      workArea.width = options.platformRect.width - inset
+    }
+    else {
+      workArea.width = dockRect.left
+    }
+  }
+  else if (distances.top <= distances.bottom) {
+    const inset = dockRect.top + dockRect.height
+    workArea.top = inset
+    workArea.height = options.platformRect.height - inset
+  }
+  else {
+    workArea.height = dockRect.top
+  }
+
+  return workArea
+}
+
+export function computeElementAnchorStyle(options: {
+  anchor: WindowAnchor
+  anchorRect: RectLike
+  platformRect: RectPosition
+  windowRect: RectSize
+}): CSSProperties {
+  const relativeAnchorRect = toRelativeRect(options.anchorRect, options.platformRect)
+  const anchorPoint = resolveAnchorPoint(relativeAnchorRect, options.anchor)
+  // We place the window by subtracting its own anchor point from the target's
+  // anchor point. That keeps "bottom-right to bottom-right" and similar cases
+  // aligned without requiring separate formulas per anchor variant.
+  const windowPoint = resolveAnchorPoint({
+    left: 0,
+    top: 0,
+    width: options.windowRect.width,
+    height: options.windowRect.height,
+  }, options.anchor)
+
+  return {
+    left: `${anchorPoint.x - windowPoint.x}px`,
+    top: `${anchorPoint.y - windowPoint.y}px`,
+  }
+}
diff --git a/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/ui/dock/dock.vue b/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/ui/dock/dock.vue
index 67f2b2321..e8fb06b9b 100644
--- a/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/ui/dock/dock.vue
+++ b/packages/scenarios-stage-tamagotchi-browser/src/components/platforms/macos-26/ui/dock/dock.vue
@@ -1,4 +1,7 @@
 <script setup lang="ts">
+import { inject, onMounted, ref, watchEffect } from 'vue'
+
+import { injectPlatformLayout } from '../../constants'
 import { Application, DockDivider, DockRoot } from '../../containers/dock'
 import { Refractive } from '../../graphics'
 import { Apps, Finder, TrashFull } from '../../icons/applications'
@@ -9,10 +12,25 @@ const props = withDefaults(defineProps<{
 }>(), {
   size: 2,
 })
+
+const dockRoot = ref<HTMLElement | null>(null)
+const platformLayout = inject(injectPlatformLayout, null)
+
+watchEffect(() => {
+  if (platformLayout) {
+    platformLayout.dock.value = dockRoot.value
+  }
+})
+
+onMounted(() => {
+  if (platformLayout) {
+    platformLayout.dock.value = dockRoot.value
+  }
+})
 </script>
 
 <template>
-  <div class="absolute right-2 top-1/2 z-1000 translate-y--1/2">
+  <div ref="dockRoot" class="absolute right-2 top-1/2 z-1000 translate-y--1/2">
     <DockRoot :size="props.size">
       <Refractive
         :refraction="{
diff --git a/packages/scenarios-stage-tamagotchi-browser/src/scenes/intro-manual-scene.vue b/packages/scenarios-stage-tamagotchi-browser/src/scenes/intro-manual-scene.vue
index 43c9d396b..9b2ca601b 100644
--- a/packages/scenarios-stage-tamagotchi-browser/src/scenes/intro-manual-scene.vue
+++ b/packages/scenarios-stage-tamagotchi-browser/src/scenes/intro-manual-scene.vue
@@ -20,8 +20,8 @@ import { WindowRoot } from '../components/platforms/macos-26/containers/window'
  * than reinterpreting each translate against a resized responsive container.
  */
 const stageWindowStyle = {
-  left: '1200px',
-  top: '400px',
+  right: '0px',
+  bottom: '0px',
 }
 
 const websocketWindowStyle = {
@@ -60,7 +60,13 @@ onMounted(async () => {
     <ScenarioCaptureRoot name="intro-chat-window">
       <PlatformRoot :dock-size="1.5">
         <template #windows>
-          <WindowRoot :style="stageWindowStyle" :frame="false" :has-shadow="false">
+          <WindowRoot
+            :style="stageWindowStyle"
+            anchor-to="bottom-right"
+            anchor-bounds="workarea"
+            :frame="false"
+            :has-shadow="false"
+          >
             <img :src="stageShot" class="w-95">
           </WindowRoot>
           <WindowRoot :style="websocketWindowStyle">
diff --git a/packages/scenarios-stage-tamagotchi-browser/vitest.config.ts b/packages/scenarios-stage-tamagotchi-browser/vitest.config.ts
new file mode 100644
index 000000000..c3292e3d1
--- /dev/null
+++ b/packages/scenarios-stage-tamagotchi-browser/vitest.config.ts
@@ -0,0 +1,15 @@
+import Vue from '@vitejs/plugin-vue'
+import Unocss from 'unocss/vite'
+
+import { defineConfig } from 'vitest/config'
+
+export default defineConfig({
+  root: import.meta.dirname,
+  plugins: [
+    Vue(),
+    Unocss(),
+  ],
+  test: {
+    include: ['src/**/*.test.ts'],
+  },
+})