added somethings

app.js

@@ -0,0 +1,73 @@
+window.onload = function(){
+    window.addEventListener('scroll', function (e){
+      if (window.pageYOffset > 100){
+        document.querySelector("header").classList.add('is-scrolling');
+      } else {
+        document.querySelector("header").classList.remove('is-scrolling');
+      }
+    });
+  const menu_btn = document.querySelector('.hamburger');
+
+  const mobile_menu = document.querySelector('.mobile-nav');
+  menu_btn.addEventListener('click', function () {
+  menu_btn.classList.toggle('is-active');
+  mobile_menu.classList.toggle('is-active');
+  });
+}
+
+var swiper = new Swiper(".mySwiper", {
+  spaceBetween: 30,
+  centeredSlides: true,
+  autoplay: {
+    delay: 2500,
+    disableOnInteraction: false,
+  },
+  pagination: {
+    el: ".swiper-pagination",
+    clickable: true,
+  },
+  navigation: {
+    nextEl: ".swiper-button-next",
+    prevEl: ".swiper-button-prev",
+  },
+});
+
+ScrollReveal().reveal('.headline');
+ ScrollReveal().reveal('.tagline', { delay: 500 });
+ScrollReveal().reveal('.punchline', { delay: 500 });
+ScrollReveal().reveal('.items');
+ScrollReveal().reveal('.sidebar .items', { container: '#sidebar' });
+ScrollReveal().reveal('.tagline', { easing: 'ease-in' }, { reset: true }, );
+
+// accordion
+var acc = document.getElementsByClassName("accordion");
+var i;
+
+for (i = 0; i < acc.length; i++) {
+  acc[i].addEventListener("click", function() {
+    this.classList.toggle("start");
+    var panel = this.nextElementSibling;
+    if (panel.style.display === "block") {
+      panel.style.display = "none";
+    } else {
+      panel.style.display = "block";
+    }
+  });
+}
+
+function openCity(evt, cityName) {
+  var i, tabcontent, tablinks;
+  tabcontent = document.getElementsByClassName("tabcontent");
+  for (i = 0; i < tabcontent.length; i++) {
+    tabcontent[i].style.display = "none";
+  }
+  tablinks = document.getElementsByClassName("tablinks");
+  for (i = 0; i < tablinks.length; i++) {
+    tablinks[i].className = tablinks[i].className.replace(" activ", "");
+  }
+  document.getElementById(cityName).style.display = "block";
+  evt.currentTarget.className += " activ";
+}
+
+// Get the element with id="defaultOpen" and click on it
+document.getElementById("defaultOpen").click();