создал addClosePhoneMenu для создания кнопки в меню для телефона

assets/css/gp-style-tablet.css

@@ -142,7 +142,7 @@
 .phone-menu__sub.open{
     left: 0;
 }
-.phone-menu__sub li:nth-child(2) a{
+.phone-menu__sub > li:nth-child(2) a{
     font-weight: 700;
     font-size: 32px;
 }

assets/js/main.js

@@ -163,6 +163,9 @@ function howPhone() {
 // how end
 
 // phone menu
+addClosePhoneMenu('.phone-menu__content');
+addClosePhoneMenu('.phone-menu__sub');
+
 let btnOpenMenu = document.querySelector('.button-menu__open');
 btnOpenMenu.onclick = function () {
     let block = document.querySelector('.phone-menu'),
@@ -201,39 +204,17 @@ phoneList.forEach(list => {
     })
 })
 
+function addClosePhoneMenu(classAdd) {
+    document.querySelectorAll(classAdd).forEach(element => {
+        let button = document.createElement('button');
+        button.className = "phone-menu-content__close";
 
-// let closeMainMenu = document.querySelector('.phone-menu-content__close.main');
-
-// closeMainMenu.onclick = function () {
-//     let phoneMenu = document.querySelector('.phone-menu'),
-//         block = document.querySelector('.phone-menu__block-content.main'),
-//         content = document.querySelector('.phone-menu__content.main');
-
-//     phoneMenu.classList.remove('active');
-//     block.style.height = 0;
-// }
-
-
-// let nextPhoneMenu = document.querySelectorAll('.phone-menu--next');
+        let referenceElement = element.firstElementChild;
 
-// nextPhoneMenu.forEach(next => {
-//     next.onclick = function () {
-//         let subName = next.dataset.menu,
-//             blockSub = document.querySelector(`.phone-menu__sub.${subName}`);
-        
-//         blockSub.classList.add('active');
-//     }
-// })
-
-// let subPhone = document.querySelectorAll('.phone-menu__sub');
-
-// subPhone.forEach(menu => {
-//     let close = menu.querySelector('.phone-menu-content__close');
+        console.log(element.insertBefore(button, referenceElement));
+    })
     
-//     close.onclick = function () {
-//         menu.classList.remove('active');
-//     }
-// })
+}
 // phone menu end
 
 // search

index.html

@@ -258,8 +258,6 @@
 
             <div class="phone-menu">
                 <div class="phone-menu__content">
-                    <button class="phone-menu-content__close"></button>
-
                     <ul class="phone-menu__list">
                         <li>
                             <a href="#">спецификация</a>
@@ -268,15 +266,12 @@
                         <li>
                             <a href="#" class="phone-menu--next" data-menu="catalog">каталог</a>
                             <ul class="phone-menu__sub phone-menu__list">
-                                <button class="phone-menu-content__close"></button>
-
                                 <li>
                                     <a href="#">Каталог</a>
                                 </li>
                                 <li>
                                     <a href="#" class="phone-menu--next">Кардио</a>
                                     <ul class="phone-menu__sub phone-menu__list">
-                                        <button class="phone-menu-content__close"></button>
                                         <li>
                                             <a href="#">Кардио</a>
                                         </li>