1 files changed, 83 insertions, 0 deletions
diff --git a/assets/js/hamburger.js b/assets/js/hamburger.js
new file mode 100644
index 0000000..1d27633
--- /dev/null
+++ b/assets/js/hamburger.js
@@ -0,0 +1,83 @@
+/**
+ * hamburger.js
+ * Hamburger menu toggle with focus trap and keyboard navigation
+ */
+
+export function initHamburger() {
+  'use strict';
+
+  const hamburgerBtn = document.getElementById('hamburger-btn');
+  const menuOverlay = document.getElementById('menu-overlay');
+  const menuLinks = document.querySelectorAll('.menu-links a');
+  const themeSwitch = document.getElementById('theme-switch');
+
+  if (!hamburgerBtn || !menuOverlay) return;
+
+  // Toggle menu on hamburger click
+  hamburgerBtn.addEventListener('click', () => {
+    const isOpen = hamburgerBtn.getAttribute('aria-expanded') === 'true';
+    setMenuOpen(!isOpen);
+  });
+
+  // Close menu on overlay click
+  menuOverlay.addEventListener('click', (e) => {
+    if (e.target === menuOverlay) {
+      setMenuOpen(false);
+    }
+  });
+
+  // Close menu on menu link click
+  menuLinks.forEach((link) => {
+    link.addEventListener('click', () => {
+      setMenuOpen(false);
+    });
+  });
+
+  // Close menu on Escape key
+  document.addEventListener('keydown', (e) => {
+    if (e.key === 'Escape') {
+      setMenuOpen(false);
+    }
+  });
+
+  // Focus trap: Tab through menu items and theme switch
+  menuOverlay.addEventListener('keydown', (e) => {
+    if (e.key !== 'Tab') return;
+
+    const focusableElements = Array.from(
+      menuOverlay.querySelectorAll('a, button')
+    );
+    const firstElement = focusableElements[0];
+    const lastElement = focusableElements[focusableElements.length - 1];
+
+    if (e.shiftKey) {
+      if (document.activeElement === firstElement) {
+        lastElement.focus();
+        e.preventDefault();
+      }
+    } else {
+      if (document.activeElement === lastElement) {
+        firstElement.focus();
+        e.preventDefault();
+      }
+    }
+  });
+
+  function setMenuOpen(isOpen) {
+    hamburgerBtn.setAttribute('aria-expanded', isOpen);
+    hamburgerBtn.classList.toggle('active', isOpen);
+    menuOverlay.classList.toggle('active', isOpen);
+
+    if (isOpen) {
+      document.body.style.overflow = 'hidden';
+      // Focus the first menu link
+      const firstLink = menuLinks[0];
+      if (firstLink) {
+        setTimeout(() => firstLink.focus(), 100);
+      }
+    } else {
+      document.body.style.overflow = '';
+      hamburgerBtn.focus();
+    }
+  }
+}