diff --git a/blocks/header/header.css b/blocks/header/header.css
index c74e6ab..0fa8918 100644
--- a/blocks/header/header.css
+++ b/blocks/header/header.css
@@ -296,23 +296,41 @@ header nav .nav-sections .default-content-wrapper > ul > li.nav-drop > p > a {
 
 /* chevron: mobile only (p::after); desktop uses li::after below */
 @media (width <= 899px) {
-  header nav .nav-sections .default-content-wrapper > ul > li.nav-drop > p::after {
-    content: '';
+  header nav .nav-sections .default-content-wrapper > ul > li.nav-drop > p {
+    padding-right: calc(var(--nav-item-padding) + 26px);
+  }
+
+  header nav .nav-sections .default-content-wrapper > ul > li.nav-drop > p > .nav-submenu-toggle {
     position: absolute;
     right: var(--nav-item-padding);
     top: 50%;
-    transform: translateY(-50%) rotate(135deg);
+    width: 24px;
+    height: 24px;
+    transform: translateY(-50%);
+    border: 0;
+    border-radius: 999px;
+    background: transparent;
+    color: inherit;
+    padding: 0;
+    cursor: pointer;
+  }
+
+  header nav .nav-sections .default-content-wrapper > ul > li.nav-drop > p > .nav-submenu-toggle::before {
+    content: '';
+    display: block;
     width: 6px;
     height: 6px;
+    margin: auto;
     border: 2px solid currentcolor;
     border-radius: 0 1px 0 0;
     border-width: 2px 2px 0 0;
     opacity: 0.6;
+    transform: rotate(135deg);
     transition: transform 0.2s ease;
   }
 
-  header nav .nav-sections .default-content-wrapper > ul > li.nav-drop[aria-expanded='true'] > p::after {
-    transform: translateY(-50%) rotate(-45deg);
+  header nav .nav-sections .default-content-wrapper > ul > li.nav-drop[aria-expanded='true'] > p > .nav-submenu-toggle::before {
+    transform: rotate(-45deg);
   }
 }
 
@@ -805,6 +823,10 @@ header nav .nav-tools .nav-language-menu a:focus-visible {
 
 /* desktop: 900px */
 @media (width >= 900px) {
+  header nav .nav-sections .default-content-wrapper > ul > li.nav-drop > p > .nav-submenu-toggle {
+    display: none;
+  }
+
   header nav {
     display: flex;
     justify-content: space-between;
diff --git a/blocks/header/header.js b/blocks/header/header.js
index 641dfcf..69a56b0 100644
--- a/blocks/header/header.js
+++ b/blocks/header/header.js
@@ -99,12 +99,48 @@ function decorateMega(li) {
 }
 
 function setupDropdown(li) {
+  const submenu = li.querySelector(':scope > ul');
+  const heading = li.querySelector(':scope > p');
+  const parentLink = li.querySelector(':scope > p > a');
+  let toggleBtn = null;
+
+  const syncToggle = () => {
+    if (!toggleBtn) return;
+    const expanded = li.getAttribute('aria-expanded') === 'true';
+    toggleBtn.setAttribute('aria-expanded', String(expanded));
+    toggleBtn.setAttribute('aria-label', expanded ? 'Collapse submenu' : 'Expand submenu');
+  };
+
+  if (submenu && heading) {
+    toggleBtn = heading.querySelector('.nav-submenu-toggle');
+    if (!toggleBtn) {
+      toggleBtn = document.createElement('button');
+      toggleBtn.type = 'button';
+      toggleBtn.className = 'nav-submenu-toggle';
+      heading.append(toggleBtn);
+    }
+    syncToggle();
+    toggleBtn.addEventListener('click', (e) => {
+      e.preventDefault();
+      e.stopPropagation();
+      if (DESKTOP.matches) return;
+      const wasOpen = li.getAttribute('aria-expanded') === 'true';
+      collapseAll(li.closest('nav'));
+      li.setAttribute('aria-expanded', wasOpen ? 'false' : 'true');
+      syncToggle();
+    });
+  }
+
   const open = () => {
     li.megaSync?.();
     collapseAll(li.closest('nav'));
     li.setAttribute('aria-expanded', 'true');
+    syncToggle();
+  };
+  const close = () => {
+    li.setAttribute('aria-expanded', 'false');
+    syncToggle();
   };
-  const close = () => li.setAttribute('aria-expanded', 'false');
 
   li.addEventListener('mouseenter', () => { if (DESKTOP.matches) open(); });
   li.addEventListener('mouseleave', (e) => {
@@ -117,16 +153,22 @@ function setupDropdown(li) {
 
   li.addEventListener('click', (e) => {
     if (!DESKTOP.matches) {
-      const submenu = li.querySelector(':scope > ul');
       const clickedSubmenuLink = submenu?.contains(e.target) && e.target.closest('a');
+      const clickedToggle = e.target.closest('.nav-submenu-toggle');
+      const clickedParentLink = parentLink && (e.target === parentLink || parentLink.contains(e.target));
+      if (clickedToggle) return;
       if (clickedSubmenuLink) {
         collapseAll(li.closest('nav'));
         close();
+      } else if (clickedParentLink) {
+        collapseAll(li.closest('nav'));
+        close();
       } else if (submenu) {
         e.preventDefault();
         const wasOpen = li.getAttribute('aria-expanded') === 'true';
         collapseAll(li.closest('nav'));
         li.setAttribute('aria-expanded', wasOpen ? 'false' : 'true');
+        syncToggle();
       }
     } else if (li.querySelector('ul')?.contains(e.target) && e.target.closest('a')) {
       collapseAll(li.closest('nav'));