diff --git a/assets/css/main.scss b/assets/css/main.scss
index 10f63fbf72b..1ea4221ceda 100644
--- a/assets/css/main.scss
+++ b/assets/css/main.scss
@@ -76,6 +76,8 @@ $tab-height: 3.3rem;
 $tab-cursor-height: 1.6rem;
 $tab-count: {{ site.data.tabs | size }};
 
+$sidebar-display: "sidebar-display";
+
 #sidebar {
   @include pl-pr(0);
   position: fixed;
@@ -273,10 +275,6 @@ $tab-count: {{ site.data.tabs | size }};
   margin: .5rem 1.5rem 2rem 1.5rem;
 }
 
-.sidebar-expand {
-  box-shadow: 4px 0 8px 0 rgba(0, 0, 0, 0.2), 6px 0 20px 0 rgba(0, 0, 0, 0.19) !important;
-}
-
 #search-result-wrapper {
   display: none;
   position: fixed;
@@ -450,7 +448,7 @@ $tab-count: {{ site.data.tabs | size }};
   background: var(--mask-bg);
   opacity: 0.5;
   z-index: 1;
-  @at-root .sidebar-expand~& {
+  @at-root [#{$sidebar-display}] & {
     display: block!important;
   }
 }
@@ -902,11 +900,6 @@ table {
   visibility: hidden !important;
 }
 
-.no-scroll {
-  position: fixed;
-  width: 100%;
-}
-
 .flex-grow-1 {
   -ms-flex-positive: 1!important;
   flex-grow: 1!important;
@@ -1003,57 +996,24 @@ table {
 
 }
 
-/* Sidebar is visibal */
-@media all and (min-width: 831px) {
-
-  #profile-wrapper {
-    margin-top: 3rem;
-  }
-
-  #search-wrapper {
-    width: 22%;
-    min-width: 150px;
-  }
-
-  /* button 'back-to-Top' position */
-  #back-to-top {
-    bottom: 5.5rem;
-    right: 1.2rem;
-  }
 
-  .topbar-up {
-    box-shadow: none !important;
-  }
-
-  #topbar-title {
-    text-align: left;
-  }
-
-  footer>div.d-flex {
-    width: 92%;
-  }
-
-}
+/* Hide Sidebar and TOC */
+@media all and (max-width: 830px) {
 
-/* iPad 9.7" horizontal */
-@media all and (min-width: 992px) and (max-width: 1024px) {
-  #main-wrapper .col-lg-11 {
-    -webkit-box-flex: 0;
-    -ms-flex: 0 0 96%;
-    flex: 0 0 96%;
-    max-width: 96%;
+  body {
+    overflow-x: hidden;
   }
-}
 
+  [#{$sidebar-display}] {
+    #sidebar {
+      transform: translateX(0);
+      box-shadow: 4px 0 8px 0 rgba(0, 0, 0, 0.2), 6px 0 20px 0 rgba(0, 0, 0, 0.19);
+    }
 
-/* Hide SideBar and TOC */
-@media all and (max-width: 830px) {
-
-  .sidebar-expand {
-    transform: translateX(0) !important;
-    ~#main-wrapper {
-      transform: translateX(#{$sidebar-width-medium}) !important;
+    #main-wrapper {
+      transform: translateX(#{$sidebar-width-medium});
     }
+
   }
 
   #sidebar {
@@ -1157,6 +1117,48 @@ table {
 }
 
 
+/* Sidebar visible */
+@media all and (min-width: 831px) {
+
+  #profile-wrapper {
+    margin-top: 3rem;
+  }
+
+  #search-wrapper {
+    width: 22%;
+    min-width: 150px;
+  }
+
+  /* button 'back-to-Top' position */
+  #back-to-top {
+    bottom: 5.5rem;
+    right: 1.2rem;
+  }
+
+  .topbar-up {
+    box-shadow: none !important;
+  }
+
+  #topbar-title {
+    text-align: left;
+  }
+
+  footer>div.d-flex {
+    width: 92%;
+  }
+
+}
+
+/* iPad 9.7" horizontal */
+@media all and (min-width: 992px) and (max-width: 1024px) {
+  #main-wrapper .col-lg-11 {
+    -webkit-box-flex: 0;
+    -ms-flex: 0 0 96%;
+    flex: 0 0 96%;
+    max-width: 96%;
+  }
+}
+
 /* Compact icons in sidebar & TOC hidden */
 @media all and (min-width: 832px) and (max-width: 1199px) {
 
diff --git a/assets/js/_src/_commons/sidebar.js b/assets/js/_src/_commons/sidebar.js
index 655f771164b..bf6551bef36 100644
--- a/assets/js/_src/_commons/sidebar.js
+++ b/assets/js/_src/_commons/sidebar.js
@@ -5,52 +5,30 @@
  * © 2018-2019 Cotes Chung
  * MIT License
  */
-$(function(){
 
-  var isExpanded = false;
+$(function() {
+
+  var sidebarUtil = (function() {
+    const ATTR_DISPLAY = "sidebar-display";
+    var isExpanded = false;
+    var body = $('body');
 
-  $("#sidebar-trigger").click(function() {
-    if (isExpanded == false) {
-      $("#sidebar").addClass("sidebar-expand");
-      openModal();
-      isExpanded = true;
-    }
-  });
-
-  $("#mask").click(function() {
-    $("#sidebar").removeClass("sidebar-expand");
-    closeModal();
-    isExpanded = false;
-  });
-
-  /**
-  * ModalHelper helpers resolve the modal scrolling issue on mobile devices
-  * https://github.com/twbs/bootstrap/issues/15852
-  * requires document.scrollingElement polyfill https://github.com/yangg/scrolling-element
-  */
-  var ModalHelper = (function(bodyCls) {
-    var scrollTop;
     return {
-      afterOpen: function() {
-        scrollTop = document.scrollingElement.scrollTop;
-        document.body.classList.add(bodyCls);
-        document.body.style.top = -scrollTop + 'px';
-      },
-      beforeClose: function() {
-        document.body.classList.remove(bodyCls);
-        // scrollTop lost after set position:fixed, restore it back.
-        document.scrollingElement.scrollTop = scrollTop;
-        document.body.style.top = '';
+      toggle: function() {
+        if (isExpanded == false) {
+          body.attr(ATTR_DISPLAY, '');
+        } else {
+          body.removeAttr(ATTR_DISPLAY);
+        }
+
+        isExpanded = !isExpanded;
       }
-    };
-  })('no-scroll');
+    }
+
+  })();
 
-  function openModal() {
-    ModalHelper.afterOpen();
-  }
+  $("#sidebar-trigger").click(sidebarUtil.toggle);
 
-  function closeModal() {
-    ModalHelper.beforeClose();
-  }
+  $('#mask').click(sidebarUtil.toggle);
 
-});
\ No newline at end of file
+});
diff --git a/assets/js/dist/_commons/sidebar.min.js b/assets/js/dist/_commons/sidebar.min.js
index 27218dcd59a..1bae9be6a90 100644
--- a/assets/js/dist/_commons/sidebar.min.js
+++ b/assets/js/dist/_commons/sidebar.min.js
@@ -1 +1 @@
-$(function(){var d=false;$("#sidebar-trigger").click(function(){if(d==false){$("#sidebar").addClass("sidebar-expand");b();d=true}});$("#mask").click(function(){$("#sidebar").removeClass("sidebar-expand");c();d=false});var a=(function(e){var f;return{afterOpen:function(){f=document.scrollingElement.scrollTop;document.body.classList.add(e);document.body.style.top=-f+"px"},beforeClose:function(){document.body.classList.remove(e);document.scrollingElement.scrollTop=f;document.body.style.top=""}}})("no-scroll");function b(){a.afterOpen()}function c(){a.beforeClose()}});
\ No newline at end of file
+$(function(){var a=(function(){const c="sidebar-display";var d=false;var b=$("body");return{toggle:function(){if(d==false){b.attr(c,"")}else{b.removeAttr(c)}d=!d}}})();$("#sidebar-trigger").click(a.toggle);$("#mask").click(a.toggle)});
\ No newline at end of file