diff --git a/CHANGELOG.md b/CHANGELOG.md
index d51a7db..5b9c92f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,7 @@ Format based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Update .vscodeignore to exclude internal scripts/tests/CI and add Content-Security-Policy to sidebar webview (Fixes #29).
 - Fix pet mood duration and unlock typing combo meter in Feed/Play commands (Fixes #23).
 - Fix accessory positioning and eye-blink transform-origins for Cat and Robot pet species (Fixes #27).
+- Automatically wake pet and reset mood from sleepy/bored when refocusing VS Code or switching active editors after system sleep (Fixes #11).
 
 ---
 
diff --git a/extension.js b/extension.js
index af08a68..4465e0f 100644
--- a/extension.js
+++ b/extension.js
@@ -413,6 +413,35 @@ function activate(context) {
     }
   });
 
+  // ── Reset Idle Mood on Activity / Focus / Wake ──
+  function resetIdleMood() {
+    lastActivity = Date.now();
+    if (!flashTimeout && (currentMood === 'sleepy' || currentMood === 'bored')) {
+      currentMood = prevErrorCount > 0 ? 'struggling' : 'happy';
+      _applyMood(currentMood);
+      updateDashboardIfOpen(stats, petName(), currentMood);
+      sidebarProvider.update();
+    }
+  }
+
+  // ── Event: Active Editor Changed ──
+  const onEditorChange = typeof vscode.window.onDidChangeActiveTextEditor === 'function'
+    ? vscode.window.onDidChangeActiveTextEditor(editor => {
+        if (editor) {
+          resetIdleMood();
+        }
+      })
+    : { dispose() {} };
+
+  // ── Event: Window Focus / System Wake ──
+  const onWindowStateChange = typeof vscode.window.onDidChangeWindowState === 'function'
+    ? vscode.window.onDidChangeWindowState(state => {
+        if (state && state.focused) {
+          resetIdleMood();
+        }
+      })
+    : { dispose() {} };
+
   // ── Idle Mood Timer (every 30 s) ──
   idleTimer = setInterval(() => {
     if (flashTimeout) return;
@@ -488,6 +517,8 @@ function activate(context) {
     onSave,
     onChange,
     onDiagnostics,
+    onEditorChange,
+    onWindowStateChange,
     onConfigChange,
     { dispose: () => {
         clearInterval(idleTimer);
diff --git a/tests/sleep.test.js b/tests/sleep.test.js
new file mode 100644
index 0000000..bfff534
--- /dev/null
+++ b/tests/sleep.test.js
@@ -0,0 +1,153 @@
+'use strict';
+
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const path = require('node:path');
+const test = require('node:test');
+const vm = require('node:vm');
+
+test('Issue #11: Resets pet mood from sleepy/bored on active editor change or window focus', (t, done) => {
+  const disposable = { dispose() {} };
+  let editorChangeHandler = null;
+  let windowStateChangeHandler = null;
+  let idleTimerCallback = null;
+
+  const statusBar = {
+    text: '',
+    tooltip: '',
+    show() {},
+    hide() {}
+  };
+
+  const vscode = {
+    DiagnosticSeverity: { Error: 0 },
+    StatusBarAlignment: { Right: 1 },
+    MarkdownString: class { constructor(value) { this.value = value; } },
+    commands: {
+      registerCommand: () => disposable
+    },
+    window: {
+      createStatusBarItem: () => statusBar,
+      registerWebviewViewProvider: () => disposable,
+      showInformationMessage: () => Promise.resolve(),
+      visibleTextEditors: [],
+      onDidChangeActiveTextEditor: handler => {
+        editorChangeHandler = handler;
+        return disposable;
+      },
+      onDidChangeWindowState: handler => {
+        windowStateChangeHandler = handler;
+        return disposable;
+      }
+    },
+    workspace: {
+      getConfiguration: () => ({ get: (key, fallback) => key === 'weeklyReview' ? false : fallback }),
+      onDidSaveTextDocument: () => disposable,
+      onDidChangeTextDocument: () => disposable,
+      onDidChangeConfiguration: () => disposable
+    },
+    languages: {
+      onDidChangeDiagnostics: () => disposable,
+      getDiagnostics: () => []
+    }
+  };
+
+  let sidebarUpdated = 0;
+  class MockSidebarProvider {
+    constructor() {}
+    update() { sidebarUpdated++; }
+  }
+
+  let dashboardUpdatedMood = null;
+  const dependencies = {
+    vscode,
+    './src/stats': {
+      StatsEngine: class {
+        getLevel() { return 1; }
+        getSnapshot() { return { level: 1, saveCount: 0, linesTyped: 0, currentStreak: 0, errorsFixed: 0 }; }
+      }
+    },
+    './src/moods': {
+      getMoodDisplay: mood => ({ statusText: `(${mood})`, label: mood, tip: '' }),
+      checkMilestones: () => [],
+      getRandomHiMessage: () => 'hi',
+      getRandomTip: () => 'tip',
+      PET_THEMES: { default: { label: 'Default' } }
+    },
+    './src/dashboard': {
+      showDashboard: () => {},
+      updateDashboardIfOpen: (stats, name, mood) => { dashboardUpdatedMood = mood; }
+    },
+    './src/sidebar': {
+      SidebarProvider: MockSidebarProvider
+    }
+  };
+
+  let currentTime = 1000000;
+  const sandbox = {
+    module: { exports: {} },
+    require: name => dependencies[name] || require(name),
+    __dirname: path.join(__dirname, '..'),
+    setTimeout: (fn) => setTimeout(fn, 0),
+    clearTimeout,
+    setInterval: (fn, ms) => {
+      if (ms === 30000) {
+        idleTimerCallback = fn;
+      }
+      return 1;
+    },
+    clearInterval: () => {},
+    Date: {
+      now: () => currentTime
+    }
+  };
+
+  const extensionCode = fs.readFileSync(path.join(__dirname, '..', 'extension.js'), 'utf8');
+  vm.runInNewContext(extensionCode, sandbox);
+  const activate = sandbox.module.exports.activate;
+  const deactivate = sandbox.module.exports.deactivate;
+
+  const mockContext = {
+    subscriptions: [],
+    globalState: { get: () => null, update: () => Promise.resolve() }
+  };
+
+  activate(mockContext);
+
+  assert.ok(typeof editorChangeHandler === 'function', 'onDidChangeActiveTextEditor handler must be registered');
+  assert.ok(typeof windowStateChangeHandler === 'function', 'onDidChangeWindowState handler must be registered');
+
+  // Simulate idle for 15 minutes (system sleep)
+  currentTime += 15 * 60 * 1000;
+  assert.ok(typeof idleTimerCallback === 'function', 'idleTimerCallback registered');
+  idleTimerCallback();
+
+  assert.ok(statusBar.text.includes('sleepy'), 'pet must be sleepy after 15m idle');
+
+  // Case 1: Switching active text editor wakes pet up
+  sidebarUpdated = 0;
+  editorChangeHandler({ document: {} });
+  assert.ok(statusBar.text.includes('happy'), 'active editor change must wake pet from sleepy to happy');
+  assert.equal(dashboardUpdatedMood, 'happy', 'dashboard updated to happy');
+  assert.ok(sidebarUpdated > 0, 'sidebar updated on wake');
+
+  // Simulate idle again to bored
+  currentTime += 5 * 60 * 1000;
+  idleTimerCallback();
+  assert.ok(statusBar.text.includes('bored'), 'pet must be bored after 5m idle');
+
+  // Case 2: Window gain focus (system wake / return to VS Code) wakes pet up
+  sidebarUpdated = 0;
+  windowStateChangeHandler({ focused: true });
+  assert.ok(statusBar.text.includes('happy'), 'window focus must wake pet from bored to happy');
+
+  // Case 3: Window blur does NOT wake pet up
+  currentTime += 12 * 60 * 1000;
+  idleTimerCallback();
+  assert.ok(statusBar.text.includes('sleepy'), 'pet must be sleepy again');
+  windowStateChangeHandler({ focused: false });
+  assert.ok(statusBar.text.includes('sleepy'), 'window blur should not alter sleepy state');
+
+  deactivate();
+  done();
+});