diff --git a/home.html b/home.html
index 3ea53b5..394374e 100644
--- a/home.html
+++ b/home.html
@@ -146,6 +146,8 @@
         }
     </style>
     <script src="theme.js"></script>
+    <link rel="manifest" href="manifest.json">
+    <meta name="theme-color" content="#0f1115">
 </head>
 <body>
 
@@ -223,5 +225,16 @@ <h2 id="chatbot-heading">🤖 Ask Your AI Tutor</h2>
 
     <script src="progress.js"></script>
     <script src="home.js"></script>
+
+    <script>
+      (function () {
+        if (!('serviceWorker' in navigator)) return;
+        window.addEventListener('load', function () {
+          navigator.serviceWorker.register('/sw.js').catch(function (err) {
+            console.warn('LearnSphere: Service Worker registration failed:', err);
+          });
+        });
+      })();
+    </script>
 </body>
 </html>
diff --git a/index.html b/index.html
index a24e633..1bb6f94 100644
--- a/index.html
+++ b/index.html
@@ -26,6 +26,9 @@
     <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.2/css/all.min.css">
     <script src="theme.js" defer></script>
     <link rel="stylesheet" href="styles.css">
+    <link rel="manifest" href="manifest.json">
+    <link rel="apple-touch-icon" href="/student.png">
+    <meta name="theme-color" content="#0f1115">
 
     <!-- Performance: Hero image priority for above-the-fold content -->
     <link rel="preload" as="image" href="student.png">
@@ -95,6 +98,17 @@ <h2>Real results.</h2>
     <script src="navbar.js" defer></script>
     <script src="script.js" defer></script>
 
+    <script>
+      (function () {
+        if (!('serviceWorker' in navigator)) return;
+        window.addEventListener('load', function () {
+          navigator.serviceWorker.register('/sw.js').catch(function (err) {
+            console.warn('LearnSphere: Service Worker registration failed:', err);
+          });
+        });
+      })();
+    </script>
+
 </body>
 
 </html>
diff --git a/manifest.json b/manifest.json
new file mode 100644
index 0000000..dd65576
--- /dev/null
+++ b/manifest.json
@@ -0,0 +1,17 @@
+{
+  "name": "LearnSphere",
+  "short_name": "LearnSphere",
+  "start_url": "/index.html",
+  "scope": "/",
+  "display": "standalone",
+  "background_color": "#0f1115",
+  "theme_color": "#0f1115",
+  "icons": [
+    {
+      "src": "/student.png",
+      "sizes": "256x256",
+      "type": "image/png"
+    }
+  ]
+}
+
diff --git a/my_progress.html b/my_progress.html
index 242acda..002220f 100644
--- a/my_progress.html
+++ b/my_progress.html
@@ -8,7 +8,10 @@
     <link rel="stylesheet" href="variables.css">
     <script src="theme.js"></script>
   <link rel="stylesheet" href="styles.css" />
+  <link rel="manifest" href="manifest.json">
+  <meta name="theme-color" content="#0f1115">
   <style>
+
     .progress-wrap {
       max-width: 980px;
       margin: 24px auto;
@@ -182,6 +185,17 @@ <h2 style="margin-top:0">Topic-wise performance</h2>
   <script src="quizProgress.js"></script>
   <script src="my_progress.js"></script>
     <script src="navbar.js"></script>
+
+    <script>
+      (function () {
+        if (!('serviceWorker' in navigator)) return;
+        window.addEventListener('load', function () {
+          navigator.serviceWorker.register('/sw.js').catch(function (err) {
+            console.warn('LearnSphere: Service Worker registration failed:', err);
+          });
+        });
+      })();
+    </script>
 </body>
 
 </html>
diff --git a/quiz/motionquiz.html b/quiz/motionquiz.html
index 62b24c4..d2cca23 100644
--- a/quiz/motionquiz.html
+++ b/quiz/motionquiz.html
@@ -64,6 +64,17 @@ <h2 id="result-title" tabindex="-1">🎉 Quiz Completed!</h2>
 
     <script src="../../quizProgress.js"></script>
     <script src="motionquiz.js"></script>
+
+    <script>
+      (function () {
+        if (!('serviceWorker' in navigator)) return;
+        window.addEventListener('load', function () {
+          navigator.serviceWorker.register('/sw.js').catch(function (err) {
+            console.warn('LearnSphere: Service Worker registration failed:', err);
+          });
+        });
+      })();
+    </script>
 </body>
 
 </html>
diff --git a/quiz/nlmquiz.html b/quiz/nlmquiz.html
index 1b7da5d..f5caeb4 100644
--- a/quiz/nlmquiz.html
+++ b/quiz/nlmquiz.html
@@ -8,6 +8,8 @@
     <link rel="stylesheet" href="../variables.css">
     <script src="../theme.js"></script>
     <link rel="stylesheet" href="nlmquiz.css">
+    <link rel="manifest" href="manifest.json">
+    <meta name="theme-color" content="#0f1115">
 </head>
 
 <body>
@@ -64,6 +66,17 @@ <h2 id="result-title" tabindex="-1">🎉 Quiz Completed!</h2>
 
     <script src="../../quizProgress.js"></script>
     <script src="nlmquiz.js"></script>
+
+    <script>
+      (function () {
+        if (!('serviceWorker' in navigator)) return;
+        window.addEventListener('load', function () {
+          navigator.serviceWorker.register('/sw.js').catch(function (err) {
+            console.warn('LearnSphere: Service Worker registration failed:', err);
+          });
+        });
+      })();
+    </script>
 </body>
 
 </html>
diff --git a/sw.js b/sw.js
new file mode 100644
index 0000000..9bf5abf
--- /dev/null
+++ b/sw.js
@@ -0,0 +1,166 @@
+/*
+ * LearnSphere PWA Service Worker
+ * Offline-first app shell caching + runtime caching for same-origin assets.
+ */
+
+const CACHE_VERSION = "v1";
+const CACHE_NAME = `learnsphere-static-${CACHE_VERSION}`;
+
+// App shell URLs to cache at install time.
+// Keep this list conservative; runtime caching covers the rest.
+const APP_SHELL_URLS = [
+  "/",
+  "/index.html",
+  "/home.html",
+  "/courses.html",
+  "/explore.html",
+  "/resources.html",
+  "/community.html",
+  "/learner.html",
+  "/parents.html",
+  "/teachers.html",
+  "/my_progress.html",
+  "/404.html",
+
+  // CSS
+  "/styles.css",
+  "/variables.css",
+  "/home.css",
+
+  // JS
+  "/script.js",
+  "/navbar.js",
+  "/home.js",
+  "/theme.js",
+  "/progress.js",
+  "/quizProgress.js",
+
+  // Images
+  "/student.png",
+
+  // Fontawesome is loaded from CDN; we do not cache it here.
+];
+
+// Query parameter helpers
+function isSameOrigin(url) {
+  return url && url.origin === self.location.origin;
+}
+
+function requestUrl(event) {
+  try {
+    return new URL(event.request.url);
+  } catch {
+    return null;
+  }
+}
+
+self.addEventListener("install", (event) => {
+  event.waitUntil(
+    (async () => {
+      const cache = await caches.open(CACHE_NAME);
+      await cache.addAll(APP_SHELL_URLS);
+      // Activate SW immediately
+      self.skipWaiting();
+    })()
+  );
+});
+
+self.addEventListener("activate", (event) => {
+  event.waitUntil(
+    (async () => {
+      // Remove old caches
+      const keys = await caches.keys();
+      await Promise.all(
+        keys.map((k) => {
+          if (k !== CACHE_NAME) return caches.delete(k);
+        })
+      );
+      self.clients.claim();
+    })()
+  );
+});
+
+self.addEventListener("fetch", (event) => {
+  const req = event.request;
+  const url = requestUrl(event);
+
+  // Only handle GET requests
+  if (req.method !== "GET") return;
+
+  // Navigation: offline fallback to cached app shell.
+  if (req.mode === "navigate" || (req.destination === "document")) {
+    event.respondWith(
+      (async () => {
+        const cache = await caches.open(CACHE_NAME);
+        try {
+          const fresh = await fetch(req);
+          // Optionally cache navigation responses (app shell only)
+          if (req.url.includes(".html")) {
+            cache.put(req, fresh.clone()).catch(() => {});
+          }
+          return fresh;
+        } catch {
+          const cachedIndex = await cache.match("/index.html");
+          const cached404 = await cache.match("/404.html");
+          return cachedIndex || cached404;
+        }
+      })()
+    );
+    return;
+  }
+
+  // Same-origin static assets: stale-while-revalidate
+  if (url && isSameOrigin(url)) {
+    const isAsset =
+      req.destination === "script" ||
+      req.destination === "style" ||
+      req.destination === "image" ||
+      req.destination === "font" ||
+      req.destination === "worker" ||
+      req.destination === "document" ||
+      req.destination === "fetch";
+
+    // Also cover common file types even when destination is not set
+    const pathname = url.pathname;
+    const fileLike =
+      pathname.endsWith(".js") ||
+      pathname.endsWith(".css") ||
+      pathname.endsWith(".png") ||
+      pathname.endsWith(".jpg") ||
+      pathname.endsWith(".jpeg") ||
+      pathname.endsWith(".gif") ||
+      pathname.endsWith(".svg") ||
+      pathname.endsWith(".webp") ||
+      pathname.endsWith(".woff") ||
+      pathname.endsWith(".woff2") ||
+      pathname.endsWith(".ttf") ||
+      pathname.endsWith(".eot");
+
+    if (isAsset || fileLike) {
+      event.respondWith(
+        (async () => {
+          const cache = await caches.open(CACHE_NAME);
+          const cached = await cache.match(req);
+          const fetchPromise = fetch(req)
+            .then((fresh) => {
+              cache.put(req, fresh.clone()).catch(() => {});
+              return fresh;
+            })
+            .catch(() => null);
+
+          if (cached) {
+            // Return cached immediately, update in background.
+            // Note: If fetch fails, cached still serves offline.
+            return cached;
+          }
+
+          const fresh = await fetchPromise;
+          return fresh || cached || new Response("", { status: 404, statusText: "Offline" });
+        })()
+      );
+    }
+  }
+});
+
+// Provide install prompt behavior is not handled here (client-side).
+
