diff --git a/index.html b/index.html
index 664d30346..d0131d4f7 100644
--- a/index.html
+++ b/index.html
@@ -41,6 +41,17 @@
                 <li><a href="#projects" onclick="scrollToSection('projects')" aria-label="Projects section" target="_self" target="_blank">Projects</a></li>
                 <li><a href="#contact" onclick="scrollToSection('contact')" aria-label="Contact section" target="_self" target="_blank">Contact</a></li>
             </ul>
+            <!-- Theme toggle button -->
+            <!-- This button allows users to switch between Dark and Light mode. -->
+            <button id="theme-toggle"
+                class="theme-toggle"
+                type="button"
+                aria-label="Toggle theme"
+                aria-pressed="false"
+                title="Toggle dark / light mode">
+              <span class="theme-icon">🌙</span>
+              <span class="visually-hidden">Toggle theme</span>
+            </button>    
             <div class="mobile-menu" onclick="toggleMobileMenu()" aria-label="Toggle navigation menu">
                 <span></span>
                 <span></span>