diff --git a/contact.html b/contact.html
index 6cc3e21..cc172af 100644
--- a/contact.html
+++ b/contact.html
@@ -12,6 +12,11 @@
       <a class="brand" href="index.html">EngineeringBuild</a>
       <div class="brand-subtitle">Telecommunications, Networking, Linux, Embedded</div>
     </div>
+    <button class="menu-toggle" type="button" aria-expanded="false" aria-label="Open menu">
+      <span></span>
+      <span></span>
+      <span></span>
+    </button>
     <nav class="site-nav" aria-label="Primary">
       <a href="index.html">Home</a>
     </nav>
diff --git a/guides/embedded.html b/guides/embedded.html
index 6f37106..971ea61 100644
--- a/guides/embedded.html
+++ b/guides/embedded.html
@@ -12,6 +12,11 @@
       <a class="brand" href="../index.html">EngineeringBuild</a>
       <div class="brand-subtitle">Telecommunications, Networking, Linux, Embedded</div>
     </div>
+    <button class="menu-toggle" type="button" aria-expanded="false" aria-label="Open menu">
+      <span></span>
+      <span></span>
+      <span></span>
+    </button>
     <nav class="site-nav" aria-label="Primary">
       <a href="../index.html">Home</a>
       <a href="../contact.html">Contact</a>
diff --git a/guides/linux.html b/guides/linux.html
index 252f502..126cbe7 100644
--- a/guides/linux.html
+++ b/guides/linux.html
@@ -12,6 +12,11 @@
       <a class="brand" href="../index.html">EngineeringBuild</a>
       <div class="brand-subtitle">Telecommunications, Networking, Linux, Embedded</div>
     </div>
+    <button class="menu-toggle" type="button" aria-expanded="false" aria-label="Open menu">
+      <span></span>
+      <span></span>
+      <span></span>
+    </button>
     <nav class="site-nav" aria-label="Primary">
       <a href="../index.html">Home</a>
       <a href="../contact.html">Contact</a>
diff --git a/guides/networking.html b/guides/networking.html
index 312084e..3f7f909 100644
--- a/guides/networking.html
+++ b/guides/networking.html
@@ -12,6 +12,11 @@
       <a class="brand" href="../index.html">EngineeringBuild</a>
       <div class="brand-subtitle">Telecommunications, Networking, Linux, Embedded</div>
     </div>
+    <button class="menu-toggle" type="button" aria-expanded="false" aria-label="Open menu">
+      <span></span>
+      <span></span>
+      <span></span>
+    </button>
     <nav class="site-nav" aria-label="Primary">
       <a href="../index.html">Home</a>
       <a href="../contact.html">Contact</a>
diff --git a/guides/telecommunications.html b/guides/telecommunications.html
index e563f4b..344b437 100644
--- a/guides/telecommunications.html
+++ b/guides/telecommunications.html
@@ -12,6 +12,11 @@
       <a class="brand" href="../index.html">EngineeringBuild</a>
       <div class="brand-subtitle">Telecommunications, Networking, Linux, Embedded</div>
     </div>
+    <button class="menu-toggle" type="button" aria-expanded="false" aria-label="Open menu">
+      <span></span>
+      <span></span>
+      <span></span>
+    </button>
     <nav class="site-nav" aria-label="Primary">
       <a href="../index.html">Home</a>
       <a href="../contact.html">Contact</a>
diff --git a/index.html b/index.html
index 4c96db5..69d7e4f 100644
--- a/index.html
+++ b/index.html
@@ -30,6 +30,12 @@
       <div class="brand-subtitle">Telecommunications, Networking, Linux, Embedded</div>
     </div>
 
+    <button class="menu-toggle" type="button" aria-expanded="false" aria-label="Open menu">
+      <span></span>
+      <span></span>
+      <span></span>
+    </button>
+
     <nav class="site-nav" aria-label="Primary">
       <div class="nav-group">
         <button class="nav-trigger" type="button" aria-haspopup="true">Services</button>
diff --git a/main.css b/main.css
index 5b14ead..ae19729 100644
--- a/main.css
+++ b/main.css
@@ -60,6 +60,10 @@ a {
   flex-wrap: wrap;
 }
 
+.menu-toggle {
+  display: none;
+}
+
 .site-nav > a,
 .nav-trigger {
   font-size: 0.92rem;
@@ -406,15 +410,50 @@ a {
 
 @media (max-width: 720px) {
   .site-header {
-    flex-direction: column;
-    align-items: flex-start;
+    display: grid;
+    grid-template-columns: 1fr auto;
+    align-items: center;
+  }
+
+  .menu-toggle {
+    display: inline-grid;
+    gap: 5px;
+    width: 44px;
+    height: 44px;
+    place-content: center;
+    border: 1px solid #e5e7eb;
+    border-radius: 8px;
+    background: #fff;
+    cursor: pointer;
+  }
+
+  .menu-toggle span {
+    display: block;
+    width: 20px;
+    height: 2px;
+    background: #111827;
   }
 
   .site-nav {
+    display: flex;
+    grid-column: 1 / -1;
     width: 100%;
     flex-direction: column;
     align-items: stretch;
     gap: 4px;
+    max-height: 0;
+    overflow: hidden;
+    padding-top: 0;
+    opacity: 0;
+    pointer-events: none;
+    transition: max-height 0.25s ease, opacity 0.2s ease, padding-top 0.2s ease;
+  }
+
+  .site-nav.is-open {
+    max-height: 700px;
+    padding-top: 12px;
+    opacity: 1;
+    pointer-events: auto;
   }
 
   .site-nav > a,
diff --git a/main.js b/main.js
index 390560a..e5cafd0 100644
--- a/main.js
+++ b/main.js
@@ -16,6 +16,12 @@ function renderSiteHeader(root) {
         <div class="brand-subtitle">Telecommunications, Networking, Linux, Embedded</div>
       </div>
 
+      <button class="menu-toggle" type="button" aria-expanded="false" aria-label="Open menu">
+        <span></span>
+        <span></span>
+        <span></span>
+      </button>
+
       <nav class="site-nav" aria-label="Primary">
         <a href="${root}index.html">Home</a>
 
@@ -84,6 +90,21 @@ document.querySelectorAll('[data-include="site-footer"]').forEach((target) => {
 
 const mobileMenuQuery = window.matchMedia('(max-width: 720px)');
 
+document.querySelectorAll('.menu-toggle').forEach((toggle) => {
+  const header = toggle.closest('.site-header');
+  const nav = header?.querySelector('.site-nav');
+
+  toggle.addEventListener('click', () => {
+    const isOpen = nav.classList.toggle('is-open');
+    toggle.setAttribute('aria-expanded', String(isOpen));
+    toggle.setAttribute('aria-label', isOpen ? 'Close menu' : 'Open menu');
+
+    if (!isOpen) {
+      closeMobileMenus();
+    }
+  });
+});
+
 function closeMobileMenus() {
   document.querySelectorAll('.nav-group.is-open').forEach((group) => {
     group.classList.remove('is-open');
@@ -113,11 +134,27 @@ document.querySelectorAll('.nav-trigger').forEach((trigger) => {
 });
 
 document.addEventListener('click', (event) => {
-  if (!mobileMenuQuery.matches || event.target.closest('.site-nav')) {
+  if (!mobileMenuQuery.matches || event.target.closest('.site-header')) {
     return;
   }
 
+  document.querySelectorAll('.site-nav.is-open').forEach((nav) => {
+    nav.classList.remove('is-open');
+  });
+  document.querySelectorAll('.menu-toggle').forEach((toggle) => {
+    toggle.setAttribute('aria-expanded', 'false');
+    toggle.setAttribute('aria-label', 'Open menu');
+  });
   closeMobileMenus();
 });
 
-mobileMenuQuery.addEventListener('change', closeMobileMenus);
+mobileMenuQuery.addEventListener('change', () => {
+  document.querySelectorAll('.site-nav.is-open').forEach((nav) => {
+    nav.classList.remove('is-open');
+  });
+  document.querySelectorAll('.menu-toggle').forEach((toggle) => {
+    toggle.setAttribute('aria-expanded', 'false');
+    toggle.setAttribute('aria-label', 'Open menu');
+  });
+  closeMobileMenus();
+});