diff --git a/wp-content/themes/kolarix-biztime/js/theme.js b/wp-content/themes/kolarix-biztime/js/theme.js
index 5d70373..284a302 100644
--- a/wp-content/themes/kolarix-biztime/js/theme.js
+++ b/wp-content/themes/kolarix-biztime/js/theme.js
@@ -1,6 +1,19 @@
 (function( $ ) {
     'use strict';
 
+    // Active header on scroll (970 Design - task 3)
+    const header = $('.header');
+
+    $(window).scroll(function() {
+        let scroll = window.pageYOffset;
+
+        if (scroll > 100) {
+            header.addClass('active');
+        } else {
+            header.removeClass('active');
+        }
+    });
+
     // Mobile navigation toggle
     $(document).ready(function($) {
         let toggleMobileNav = function() {