diff --git a/src/assets/js/main.js b/src/assets/js/main.js
index 7b0b75c..fb5fdd2 100644
--- a/src/assets/js/main.js
+++ b/src/assets/js/main.js
@@ -16,7 +16,6 @@ document.addEventListener("DOMContentLoaded", () => {
 	stickyHeaderFuncionality();
 	applyMenuItemClasses();
 	evaluateHeaderPosition();
-	mobileMenuFunctionality();
 });
 
 window.stickyHeaderFuncionality = () => {
@@ -33,54 +32,19 @@ window.evaluateHeaderPosition = () => {
 		);
 		headerElement.classList.add(...stickyClasses);
 		headerElement.classList.remove(...unstickyClasses);
-		document.getElementById("menu").classList.add("top-[56px]");
-		document.getElementById("menu").classList.remove("top-[75px]");
 	} else {
 		headerElement.firstElementChild.classList.remove(...stickyClassesContainer);
 		headerElement.firstElementChild.classList.add(...unstickyClassesContainer);
 		headerElement.classList.add(...unstickyClasses);
 		headerElement.classList.remove(...stickyClasses);
-		document.getElementById("menu").classList.remove("top-[56px]");
-		document.getElementById("menu").classList.add("top-[75px]");
 	}
 };
 
 window.applyMenuItemClasses = () => {
-	const menuItems = document.querySelectorAll("#menu a");
+	const menuItems = document.querySelectorAll("#menu a, #mobileMenu a");
 	for (let i = 0; i < menuItems.length; i++) {
 		if (menuItems[i].pathname === window.location.pathname) {
 			menuItems[i].classList.add("text-neutral-900", "dark:text-white");
 		}
 	}
 };
-
-function mobileMenuFunctionality() {
-	document.getElementById("openMenu").addEventListener("click", () => {
-		openMobileMenu();
-	});
-
-	document.getElementById("closeMenu").addEventListener("click", () => {
-		closeMobileMenu();
-	});
-}
-
-window.openMobileMenu = () => {
-	document.getElementById("openMenu").classList.add("hidden");
-	document.getElementById("closeMenu").classList.remove("hidden");
-	document.getElementById("menu").classList.remove("hidden");
-	document.getElementById("mobileMenuBackground").classList.add("opacity-0");
-	document.getElementById("mobileMenuBackground").classList.remove("hidden");
-
-	setTimeout(() => {
-		document
-			.getElementById("mobileMenuBackground")
-			.classList.remove("opacity-0");
-	}, 1);
-};
-
-window.closeMobileMenu = () => {
-	document.getElementById("closeMenu").classList.add("hidden");
-	document.getElementById("openMenu").classList.remove("hidden");
-	document.getElementById("menu").classList.add("hidden");
-	document.getElementById("mobileMenuBackground").classList.add("hidden");
-};
diff --git a/src/components/header.astro b/src/components/header.astro
index faf8124..b49bfea 100644
--- a/src/components/header.astro
+++ b/src/components/header.astro
@@ -29,6 +29,9 @@ const menus = {
 const currentMenus = menus[currentLang] || menus.fr;
 ---
 
+<!-- Hidden checkbox to control mobile menu state (CSS-only) -->
+<input type="checkbox" id="menuToggle" class="hidden peer" aria-hidden="true" />
+
 <!-- This is an invisible div with relative position so that it takes up the height of the menu (because menu is absolute/fixed) -->
 <div class="relative w-full h-20 opacity-0 pointer-events-none"></div>
 <header id="header" class="absolute top-0 z-50 w-full h-20">
@@ -36,18 +39,13 @@ const currentMenus = menus[currentLang] || menus.fr;
     class="flex items-center justify-between h-full max-w-5xl pl-6 pr-4 mx-auto border-b border-l-0 border-r-0 border-transparent select-none lg:border-r lg:border-l lg:rounded-b-xl"
   >
     <Logo />
-    <button
-      id="mobileMenuBackground"
-      type="button"
-      aria-label={t('ui', 'closeMenu', currentLang)}
-      class="fixed inset-0 z-20 hidden w-screen h-screen duration-300 ease-out bg-white/90 dark:bg-neutral-950/90 appearance-none border-0 p-0 cursor-default"
-    >
-    </button>
     <nav
       class="relative z-30 flex flex-row-reverse justify-start w-full text-sm sm:justify-end text-neutral-500 dark:text-neutral-400 sm:flex-row"
     >
-      <div
-        id="openMenu"
+      <!-- Hamburger button (open) -->
+      <label
+        for="menuToggle"
+        aria-label={t('ui', 'openMenu', currentLang)}
         class="flex flex-col items-end justify-center w-6 h-6 ml-4 cursor-pointer sm:hidden"
       >
         <svg
@@ -59,38 +57,14 @@ const currentMenus = menus[currentLang] || menus.fr;
           viewBox="0 0 24 24"
           stroke="currentColor"><path d="M4 8h16M4 16h16"></path></svg
         >
-      </div>
-      <div
-        id="closeMenu"
-        class="flex flex-col items-end justify-center hidden w-6 h-6 ml-4 -translate-x-1 cursor-pointer sm:hidden"
-      >
-        <svg
-          class="w-6 h-6 text-neutral-600 dark:text-neutral-200"
-          fill="none"
-          stroke-linecap="round"
-          stroke-linejoin="round"
-          stroke-width="2"
-          viewBox="0 0 24 24"
-          stroke="currentColor"><path d="M6 18L18 6M6 6l12 12"></path></svg
-        >
-      </div>
-      <div
-        id="menu"
-        class="fixed top-[75px] ease-out duration-300 sm:top-0 w-full left-0 sm:py-0 pt-7 pb-4 dm:mx-0 left-0 z-40 flex-col items-end justify-start hidden w-full h-auto text-sm sm:text-base sm:h-auto sm:relative sm:flex-row sm:flex sm:text-sm sm:w-auto sm:pr-0 sm:pt-0"
-      >
-        <div
-          class="absolute inset-0 top-0 right-0 block w-full h-full px-3 sm:hidden"
-        >
-          <div
-            class="relative w-full h-full bg-white border border-dashed border-neutral-300 dark:border-neutral-700 backdrop-blur-sm rounded-xl dark:bg-neutral-950"
-          >
-          </div>
-        </div>
+      </label>
+      <!-- Desktop menu -->
+      <div id="menu" class="hidden sm:flex sm:flex-row sm:h-auto sm:w-auto sm:text-sm">
         {
           currentMenus.map((menu) => (
             <a
               href={menu.url}
-              class="relative flex items-center justify-center w-full px-3 py-2 font-medium tracking-wide text-center duration-200 ease-out sm:py-0 sm:mb-0 md:w-auto hover:text-neutral-900 dark:hover:text-white"
+              class="relative flex items-center justify-center px-3 font-medium tracking-wide text-center duration-200 ease-out hover:text-neutral-900 dark:hover:text-white"
             >
               {menu.name}
             </a>
@@ -101,8 +75,64 @@ const currentMenus = menus[currentLang] || menus.fr;
   </div>
 </header>
 
-<script is:inline>
-  document.getElementById('mobileMenuBackground').addEventListener('click', function () {
-    window.closeMobileMenu();
-  });
-</script>
+<!-- Mobile fullscreen menu (sibling of checkbox, outside header) -->
+<div
+  id="mobileMenu"
+  class="mobile-menu fixed top-0 left-0 z-[100] flex-col items-center justify-center bg-white dark:bg-neutral-950"
+>
+  <!-- Close button -->
+  <label
+    for="menuToggle"
+    aria-label={t('ui', 'closeMenu', currentLang)}
+    class="absolute top-6 right-6 w-8 h-8 cursor-pointer"
+  >
+    <svg
+      class="w-8 h-8 text-neutral-600 dark:text-neutral-200"
+      fill="none"
+      stroke-linecap="round"
+      stroke-linejoin="round"
+      stroke-width="2"
+      viewBox="0 0 24 24"
+      stroke="currentColor"><path d="M6 18L18 6M6 6l12 12"></path></svg
+    >
+  </label>
+  {
+    currentMenus.map((menu) => (
+      <a
+        href={menu.url}
+        class="flex items-center justify-center px-3 py-4 text-2xl font-medium tracking-wide text-neutral-700 dark:text-neutral-300 hover:text-neutral-900 dark:hover:text-white duration-200 ease-out"
+      >
+        {menu.name}
+      </a>
+    ))
+  }
+</div>
+
+<style>
+  /* Mobile menu: hidden by default, shown when checkbox is checked */
+  .mobile-menu {
+    display: none;
+    overflow: hidden;
+    width: 100dvw;
+    height: 100dvh;
+  }
+
+  #menuToggle:checked ~ .mobile-menu {
+    display: flex;
+  }
+
+  /* Hide menu on desktop regardless of checkbox state */
+  @media (min-width: 640px) {
+    .mobile-menu {
+      display: none !important;
+    }
+  }
+</style>
+<style is:global>
+  /* Block page scroll when mobile menu is open */
+  html:has(#menuToggle:checked) body {
+    position: fixed;
+    inset: 0;
+    overflow: hidden;
+  }
+</style>
diff --git a/src/utils/i18n.ts b/src/utils/i18n.ts
index 3532022..a52574b 100644
--- a/src/utils/i18n.ts
+++ b/src/utils/i18n.ts
@@ -64,6 +64,7 @@ export const translations = {
 		lightMode: { fr: 'Mode clair', en: 'Light mode', ar: 'الوضع الفاتح' },
 	},
 	ui: {
+		openMenu: { fr: 'Ouvrir le menu', en: 'Open menu', ar: 'فتح القائمة' },
 		closeMenu: { fr: 'Fermer le menu', en: 'Close menu', ar: 'إغلاق القائمة' },
 		changeTheme: { fr: 'Changer le thème', en: 'Change theme', ar: 'تغيير المظهر' },
 		themeAuto: { fr: 'Thème : automatique', en: 'Theme: auto', ar: 'المظهر: تلقائي' },