сделал js для открытия меню

assets/js/main.js

@@ -142,6 +142,32 @@ function howPhone() {
 }
 // how end
 
+// phone menu
+let btnOpenMenu = document.querySelector('.button-menu__open');
+
+btnOpenMenu.onclick = function () {
+    let phoneMenu = document.querySelector('.phone-menu'),
+        block = document.querySelector('.phone-menu__block-content.main'),
+        content = document.querySelector('.phone-menu__content.main'),
+        newHeigh = content.offsetHeight + 'px';
+
+    phoneMenu.classList.add('active');
+    block.style.height = newHeigh;
+}
+
+let nextPhoneMenu = document.querySelectorAll('.phone-menu--next');
+
+nextPhoneMenu.forEach(next => {
+    next.onclick = function () {
+        let subName = next.dataset.menu,
+            blockSub = document.querySelector(`.phone-menu__sub.${subName}`);
+        
+        blockSub.classList.add('active');
+    }
+})
+// phone menu
+
+
 // resize
 window.addEventListener('resize', () => {
     let screenWidth = window.screen.width;