diff --git a/ecosystem.config.js b/ecosystem.config.js
index 14630b4..fa4e6cc 100644
--- a/ecosystem.config.js
+++ b/ecosystem.config.js
@@ -1,20 +1,23 @@
 module.exports = {
-  apps: [{
-    name: "expressjs-blog",
-    script: "./src/app.js",
-    instances: 1, // or "max" for cluster mode
-    exec_mode: "fork", // or "cluster"
-    env: {
-      NODE_ENV: "development"
+  apps: [
+    {
+      name: "expressjs-blog",
+      script: "./src/app.js",
+      instances: 1, // or "max" for cluster mode
+      exec_mode: "fork", // or "cluster"
+      env: {
+        NODE_ENV: "development",
+        PORT: 3400,
+      },
+      env_production: {
+        NODE_ENV: "production",
+        PORT: 3000,
+      },
+      ignore_watch: ["node_modules", "logs"],
+      log_date_format: "YYYY-MM-DD HH:mm Z",
+      error_file: "./logs/err.log",
+      out_file: "./logs/out.log",
+      pid_file: "./pids/pm2.pid",
     },
-    env_production: {
-      NODE_ENV: "production",
-      PORT: 3000
-    },
-    log_date_format: "YYYY-MM-DD HH:mm Z",
-    error_file: "./logs/err.log",
-    out_file: "./logs/out.log",
-    pid_file: "./pids/pm2.pid"
-  }]
-}
-
+  ],
+};
diff --git a/package.json b/package.json
index cd30789..c490c7d 100644
--- a/package.json
+++ b/package.json
@@ -7,9 +7,9 @@
     "test": "echo \"Error: no test specified\" && exit 1",
     "start": "nodemon ./src/app.js --trace-exit",
     "maildev": "maildev",
-    "dev": "./node_modules/pm2/bin/pm2 start --env development --watch",
-    "prod": "./node_modules/pm2/bin/pm2 start --env production",
-    "stop": "node_modules/pm2/bin/pm2 stop expressjs-blog"
+    "dev": "./node_modules/pm2/bin/pm2 ecosystem.config.js start --env development --watch",
+    "prod": "./node_modules/pm2/bin/pm2 ecosystem.config.js start --env production",
+    "stop": "node_modules/pm2/bin/pm2 delete expressjs-blog"
   },
   "keywords": [],
   "author": "",
diff --git a/public/js/post.js b/public/js/post.js
new file mode 100644
index 0000000..3a4bb5e
--- /dev/null
+++ b/public/js/post.js
@@ -0,0 +1,122 @@
+// Syntax Highlighting with Prism.js (include Prism CSS/JS separately)
+// Automatically highlight all <pre><code> blocks
+document.querySelectorAll("pre code").forEach((block) => {
+  Prism.highlightElement(block);
+});
+
+// Copy-to-Clipboard Buttons for Code Blocks
+document.querySelectorAll("pre").forEach((pre) => {
+  const btn = document.createElement("button");
+  btn.textContent = "Copy";
+  btn.type = "button";
+  btn.className = "copy-btn";
+  btn.style.position = "absolute";
+  btn.style.top = "0.5rem";
+  btn.style.right = "0.5rem";
+
+  btn.addEventListener("click", () => {
+    const code = pre.querySelector("code");
+    if (!code) return;
+    navigator.clipboard.writeText(code.innerText).then(() => {
+      btn.textContent = "Copied";
+      setTimeout(() => (btn.textContent = "Copy"), 2000);
+    });
+  });
+
+  pre.style.position = "relative";
+  pre.appendChild(btn);
+});
+
+// Table of Contents Generation from h2, h3 in .post-content
+(function generateTOC() {
+  const content = document.querySelector(".post-content");
+  if (!content) return;
+  const tocContainer = document.createElement("nav");
+  tocContainer.className = "toc";
+  const tocList = document.createElement("ul");
+
+  content.querySelectorAll("h2, h3").forEach((heading) => {
+    if (!heading.id)
+      heading.id = heading.textContent
+        .trim()
+        .toLowerCase()
+        .replace(/\s+/g, "-");
+
+    const li = document.createElement("li");
+    li.className = heading.tagName.toLowerCase();
+
+    const a = document.createElement("a");
+    a.href = `#${heading.id}`;
+    a.textContent = heading.textContent;
+
+    li.appendChild(a);
+    tocList.appendChild(li);
+  });
+
+  tocContainer.appendChild(tocList);
+
+  // Insert TOC before post content or in sidebar if exists
+  const sidebar = document.querySelector(".sidebar nav");
+  if (sidebar) sidebar.appendChild(tocContainer);
+  else content.parentNode.insertBefore(tocContainer, content);
+})();
+
+// Smooth Scroll for Anchor Links
+document.querySelectorAll('a[href^="#"]').forEach((anchor) => {
+  anchor.addEventListener("click", (e) => {
+    const target = document.querySelector(anchor.getAttribute("href"));
+    if (!target) return;
+    e.preventDefault();
+    target.scrollIntoView({ behavior: "smooth" });
+  });
+});
+
+// Dark Mode Toggle
+(function darkModeToggle() {
+  const toggle = document.createElement("button");
+  toggle.textContent = "Toggle Dark Mode";
+  toggle.id = "dark-mode-toggle";
+  document.body.prepend(toggle);
+
+  function applyMode(dark) {
+    document.documentElement.setAttribute(
+      "data-theme",
+      dark ? "dark" : "light"
+    );
+    localStorage.setItem("darkMode", dark);
+  }
+
+  toggle.addEventListener("click", () => {
+    const dark = document.documentElement.getAttribute("data-theme") === "dark";
+    applyMode(!dark);
+  });
+
+  // Initialize from saved preference or system
+  const saved = localStorage.getItem("darkMode");
+  if (saved !== null) applyMode(saved === "true");
+  else applyMode(window.matchMedia("(prefers-color-scheme: dark)").matches);
+})();
+
+// External Link Detection and Attributes
+document.querySelectorAll('.post-content a[href^="http"]').forEach((link) => {
+  if (new URL(link.href).origin !== location.origin) {
+    link.setAttribute("target", "_blank");
+    link.setAttribute("rel", "noopener noreferrer");
+    // Optionally append icon for external link:
+    const extIcon = document.createElement("span");
+    extIcon.textContent = " ↗";
+    extIcon.setAttribute("aria-hidden", "true");
+    link.appendChild(extIcon);
+  }
+});
+
+// Accessibility: Focus outlines on keyboard navigation
+(function manageFocusOutline() {
+  function handleFirstTab(e) {
+    if (e.key === "Tab") {
+      document.body.classList.add("user-is-tabbing");
+      window.removeEventListener("keydown", handleFirstTab);
+    }
+  }
+  window.addEventListener("keydown", handleFirstTab);
+})();
diff --git a/src/app.js b/src/app.js
index f757bed..8f25507 100644
--- a/src/app.js
+++ b/src/app.js
@@ -18,6 +18,8 @@
       return null;
     },
   },
+  defaultLayout: "main",
+  extname: ".handlebars",
   runtimeOptions: {
     allowProtoPropertiesByDefault: true,
     allowProtoMethodsByDefault: true,
diff --git a/src/routes/index.js b/src/routes/index.js
index 828573e..38539cd 100644
--- a/src/routes/index.js
+++ b/src/routes/index.js
@@ -1,60 +1,15 @@
 // src/routes/index.js
 const express = require("express");
 const router = express.Router();
-const { marked } = require("marked");
-const fs = require("fs").promises;
-const path = require("path");
-const matter = require("gray-matter");
 const contact = require("./contact");
 const about = require("./about");
+const post = require("./post");
 
 const getBaseContext = require("../utils/baseContext");
 
 router.use(contact);
 router.use(about);
-router.get("/post/:year/:month/:name", async (req, res, next) => {
-  const { year, month, name } = req.params;
-
-  // Validate year: 4 digits only
-  if (!/^\d{4}$/.test(year)) {
-    const error = new Error("Invalid year parameter.");
-    error.statusCode = 400;
-    return next(error);
-  }
-
-  // Validate month: 01-12 only
-  if (!/^(0[1-9]|1[0-2])$/.test(month)) {
-    const error = new Error("Invalid month parameter.");
-    error.statusCode = 400;
-    return next(error);
-  }
-
-  // Validate name: allow alphanumeric, dash, underscore only (no dots, no slashes)
-  if (!/^[a-zA-Z0-9_-]+$/.test(name)) {
-    const error = new Error("Invalid post name parameter.");
-    error.statusCode = 400;
-    return next(error);
-  }
-
-  const mdPath = path.join(__dirname, "../../posts", year, month, `${name}.md`);
-
-  try {
-    const fileContent = await fs.readFile(mdPath, "utf8");
-    const { data: frontmatter, content } = matter(fileContent);
-    const htmlContent = marked(content);
-    const context = await getBaseContext({
-      title: frontmatter.title,
-      date: frontmatter.date,
-      author: frontmatter.author,
-      content: htmlContent,
-    });
-    res.render("pages/post", context);
-  } catch (err) {
-    const error = new Error("The requested blog post could not be found.");
-    error.statusCode = 404;
-    next(error);
-  }
-});
+router.get("/post/:year/:month/:name", post);
 router.get("/", async (req, res) => {
   const context = await getBaseContext({
     title: "Blog Home",
diff --git a/src/routes/post.js b/src/routes/post.js
new file mode 100644
index 0000000..86151ac
--- /dev/null
+++ b/src/routes/post.js
@@ -0,0 +1,53 @@
+// src/routes/index.js
+const express = require("express");
+const router = express.Router();
+const { marked } = require("marked");
+const fs = require("fs").promises;
+const path = require("path");
+const matter = require("gray-matter");
+
+const getBaseContext = require("../utils/baseContext");
+
+module.exports = async (req, res, next) => {
+  const { year, month, name } = req.params;
+
+  // Validate year: 4 digits only
+  if (!/^\d{4}$/.test(year)) {
+    const error = new Error("Invalid year parameter.");
+    error.statusCode = 400;
+    return next(error);
+  }
+
+  // Validate month: 01-12 only
+  if (!/^(0[1-9]|1[0-2])$/.test(month)) {
+    const error = new Error("Invalid month parameter.");
+    error.statusCode = 400;
+    return next(error);
+  }
+
+  // Validate name: allow alphanumeric, dash, underscore only (no dots, no slashes)
+  if (!/^[a-zA-Z0-9_-]+$/.test(name)) {
+    const error = new Error("Invalid post name parameter.");
+    error.statusCode = 400;
+    return next(error);
+  }
+
+  const mdPath = path.join(__dirname, "../../posts", year, month, `${name}.md`);
+
+  try {
+    const fileContent = await fs.readFile(mdPath, "utf8");
+    const { data: frontmatter, content } = matter(fileContent);
+    const htmlContent = marked(content);
+    const context = await getBaseContext({
+      title: frontmatter.title,
+      date: frontmatter.date,
+      author: frontmatter.author,
+      content: htmlContent,
+    });
+    res.render("pages/post", context);
+  } catch (err) {
+    const error = new Error("The requested blog post could not be found.");
+    error.statusCode = 404;
+    next(error);
+  }
+};
diff --git a/src/views/layouts/main.handlebars b/src/views/layouts/main.handlebars
index ba372a5..abe308f 100644
--- a/src/views/layouts/main.handlebars
+++ b/src/views/layouts/main.handlebars
@@ -24,6 +24,7 @@
   <footer>
     {{> footer}}
   </footer>
+  {{{_sections.scripts}}}
 </body>
 
 </html>
diff --git a/src/views/pages/post.handlebars b/src/views/pages/post.handlebars
index e09b498..f64a83d 100644
--- a/src/views/pages/post.handlebars
+++ b/src/views/pages/post.handlebars
@@ -4,3 +4,6 @@
 <div class="post-content">
   {{{content}}}
 </div>
+{{#section "scripts"}}
+<script src="/static/js/post.js"></script>
+{{/section}}