diff --git a/apps/common/main/lib/util/htmlutils.js b/apps/common/main/lib/util/htmlutils.js
index 77392abde..d75a54d0a 100644
--- a/apps/common/main/lib/util/htmlutils.js
+++ b/apps/common/main/lib/util/htmlutils.js
@@ -88,9 +88,11 @@ if ( !!params.uitheme && checkLocalStorage && !localStorage.getItem("ui-theme-id
 }
 
 var ui_theme_name = checkLocalStorage && localStorage.getItem("ui-theme-id") ? localStorage.getItem("ui-theme-id") : params.uitheme;
+var ui_theme_type;
 if ( !ui_theme_name ) {
     if ( window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches ) {
         ui_theme_name = 'theme-dark';
+        ui_theme_type = 'dark';
         checkLocalStorage && localStorage.removeItem("ui-theme");
     }
 }
@@ -100,7 +102,7 @@ if ( !!ui_theme_name ) {
 
 if ( checkLocalStorage ) {
     let current_theme = localStorage.getItem("ui-theme");
-    if ( !!current_theme && /type":\s*"dark/.test(current_theme) ) {
+    if ( !!current_theme && /type":\s*"dark/.test(current_theme) || ui_theme_type == 'dark' ) {
         document.body.classList.add("theme-type-dark");
 
         let content_theme = localStorage.getItem("content-theme");
diff --git a/apps/common/mobile/lib/controller/Themes.js b/apps/common/mobile/lib/controller/Themes.js
index 768fdf9bf..2c076a15f 100644
--- a/apps/common/mobile/lib/controller/Themes.js
+++ b/apps/common/mobile/lib/controller/Themes.js
@@ -12,6 +12,51 @@ class ThemesController {
                 id: 'theme-light',
                 type: 'light'
             }};
+
+        this.name_colors = [
+            "canvas-background",
+            "canvas-content-background",
+            "canvas-page-border",
+
+            "canvas-ruler-background",
+            "canvas-ruler-border",
+            "canvas-ruler-margins-background",
+            "canvas-ruler-mark",
+            "canvas-ruler-handle-border",
+            "canvas-ruler-handle-border-disabled",
+
+            "canvas-high-contrast",
+            "canvas-high-contrast-disabled",
+
+            "canvas-cell-border",
+            "canvas-cell-title-border",
+            "canvas-cell-title-border-hover",
+            "canvas-cell-title-border-selected",
+            "canvas-cell-title-hover",
+            "canvas-cell-title-selected",
+
+            "canvas-dark-cell-title",
+            "canvas-dark-cell-title-hover",
+            "canvas-dark-cell-title-selected",
+            "canvas-dark-cell-title-border",
+            "canvas-dark-cell-title-border-hover",
+            "canvas-dark-cell-title-border-selected",
+            "canvas-dark-content-background",
+            "canvas-dark-page-border",
+
+            "canvas-scroll-thumb",
+            "canvas-scroll-thumb-hover",
+            "canvas-scroll-thumb-pressed",
+            "canvas-scroll-thumb-border",
+            "canvas-scroll-thumb-border-hover",
+            "canvas-scroll-thumb-border-pressed",
+            "canvas-scroll-arrow",
+            "canvas-scroll-arrow-hover",
+            "canvas-scroll-arrow-pressed",
+            "canvas-scroll-thumb-target",
+            "canvas-scroll-thumb-target-hover",
+            "canvas-scroll-thumb-target-pressed",
+        ];
     }
 
     init() {
@@ -41,6 +86,16 @@ class ThemesController {
         return !!obj ? JSON.parse(obj).type === 'dark' : false;
     }
 
+    get_current_theme_colors(colors) {
+        let out_object = {};
+        const style = getComputedStyle(document.body);
+        colors.forEach((item, index) => {
+            out_object[item] = style.getPropertyValue('--' + item).trim()
+        })
+
+        return out_object;
+    }
+
     switchDarkTheme(dark) {
         const theme = typeof dark == 'object' ? dark : this.themes_map[dark ? 'dark' : 'light'];
         const refresh_only = !!arguments[1];
@@ -53,7 +108,11 @@ class ThemesController {
         $body.addClass(`theme-type-${theme.type}`);
 
         const on_engine_created = api => {
-            api.asc_setSkin(theme.id);
+            let obj = this.get_current_theme_colors(this.name_colors);
+            obj.type = theme.type;
+            obj.name = theme.id;
+
+            api.asc_setSkin(obj);
         };
 
         const api = Common.EditorApi ? Common.EditorApi.get() : undefined;
diff --git a/apps/common/mobile/resources/less/colors-table-dark.less b/apps/common/mobile/resources/less/colors-table-dark.less
index e97d2d9a0..972f85d49 100644
--- a/apps/common/mobile/resources/less/colors-table-dark.less
+++ b/apps/common/mobile/resources/less/colors-table-dark.less
@@ -33,12 +33,53 @@
 
         --image-border-types-filter: invert(100%) brightness(4);
 
-        --canvas-content-background: #fff;
-        
         --active-opacity-word: fade(#446995, 20%);
         --active-opacity-slide: fade(#AA5252, 20%);
         --active-opacity-cell: fade(#40865C, 20%);
 
         --image-border-types-filter: invert(100%) brightness(4);
+
+        // Canvas
+
+        --canvas-background: #555;
+        --canvas-content-background: #fff;
+        --canvas-page-border: #555;
+
+        --canvas-ruler-background: #555;
+        --canvas-ruler-border: #2A2A2A;
+        --canvas-ruler-margins-background: #444;
+        --canvas-ruler-mark: #b6b6b6;
+        --canvas-ruler-handle-border: #b6b6b6;
+        --canvas-ruler-handle-border-disabled: #808080;
+
+        --canvas-high-contrast: #fff;
+        --canvas-high-contrast-disabled: #ccc;
+
+        --canvas-cell-border: fade(#000, 10%);
+        --canvas-cell-title-border: #757575;
+        --canvas-cell-title-border-hover: #858585;
+        --canvas-cell-title-border-selected: #9e9e9e;
+        --canvas-cell-title-hover: #787878;
+        --canvas-cell-title-selected: #939393;
+
+        --canvas-dark-cell-title: #111;
+        --canvas-dark-cell-title-hover: #000;
+        --canvas-dark-cell-title-selected: #333;
+        --canvas-dark-cell-title-border: #282828;
+        --canvas-dark-cell-title-border-hover: #191919;
+        --canvas-dark-cell-title-border-selected: #474747;
+
+        --canvas-scroll-thumb: #404040;
+        --canvas-scroll-thumb-hover: #999;
+        --canvas-scroll-thumb-pressed: #adadad;
+        --canvas-scroll-thumb-border: #2a2a2a;
+        --canvas-scroll-thumb-border-hover: #999;
+        --canvas-scroll-thumb-border-pressed: #adadad;
+        --canvas-scroll-arrow: #999;
+        --canvas-scroll-arrow-hover: #404040;
+        --canvas-scroll-arrow-pressed: #404040;
+        --canvas-scroll-thumb-target: #999;
+        --canvas-scroll-thumb-target-hover: #404040;
+        --canvas-scroll-thumb-target-pressed: #404040;
     }
 }
\ No newline at end of file
diff --git a/apps/common/mobile/resources/less/colors-table.less b/apps/common/mobile/resources/less/colors-table.less
index 0ce2667ca..331ca6779 100644
--- a/apps/common/mobile/resources/less/colors-table.less
+++ b/apps/common/mobile/resources/less/colors-table.less
@@ -29,13 +29,56 @@
 
     --component-disabled-opacity: .4;
 
-    --canvas-content-background: #fff;
-
     --active-opacity-word: fade(#446995, 30%);
     --active-opacity-slide: fade(#AA5252, 30%);
     --active-opacity-cell: fade(#40865C, 30%);
 
     --image-border-types-filter: none;
+
+    // Canvas
+
+    --canvas-background: #eee;
+    --canvas-content-background: #fff;
+    --canvas-page-border: #ccc;
+
+    --canvas-ruler-background: #fff;
+    --canvas-ruler-border: #cbcbcb;
+    --canvas-ruler-margins-background: #d9d9d9;
+    --canvas-ruler-mark: #555;
+    --canvas-ruler-handle-border: #555;
+    --canvas-ruler-handle-border-disabled: #aaa;
+
+    --canvas-high-contrast: #000;
+    --canvas-high-contrast-disabled: #666;
+
+    --canvas-cell-border: fade(#000, 10%);
+    --canvas-cell-title-hover: #dfdfdf;
+    --canvas-cell-title-selected: #cfcfcf;
+    --canvas-cell-title-border: #d8d8d8;
+    --canvas-cell-title-border-hover: #c9c9c9;
+    --canvas-cell-title-border-selected: #bbb;
+
+    --canvas-dark-cell-title: #444;
+    --canvas-dark-cell-title-hover: #666 ;
+    --canvas-dark-cell-title-selected: #111;
+    --canvas-dark-cell-title-border: #3d3d3d;
+    --canvas-dark-cell-title-border-hover: #5c5c5c;
+    --canvas-dark-cell-title-border-selected: #0f0f0f;
+    --canvas-dark-content-background: #3a3a3a;
+    --canvas-dark-page-border: #2a2a2a;
+
+    --canvas-scroll-thumb: #f7f7f7;
+    --canvas-scroll-thumb-hover: #c0c0c0;
+    --canvas-scroll-thumb-pressed: #adadad;
+    --canvas-scroll-thumb-border: #cbcbcb;
+    --canvas-scroll-thumb-border-hover: #cbcbcb;
+    --canvas-scroll-thumb-border-pressed: #adadad;
+    --canvas-scroll-arrow: #adadad;
+    --canvas-scroll-arrow-hover: #f7f7f7;
+    --canvas-scroll-arrow-pressed: #f7f7f7;
+    --canvas-scroll-thumb-target: #c0c0c0;
+    --canvas-scroll-thumb-target-hover: #f7f7f7;
+    --canvas-scroll-thumb-target-pressed: #f7f7f7;
 }
 
 @brand-word: var(--brand-word);
diff --git a/apps/documenteditor/forms/app/controller/SearchBar.js b/apps/documenteditor/forms/app/controller/SearchBar.js
index 53ce27e4f..2465a8466 100644
--- a/apps/documenteditor/forms/app/controller/SearchBar.js
+++ b/apps/documenteditor/forms/app/controller/SearchBar.js
@@ -127,7 +127,7 @@ define([
 
         onInputSearchChange: function (text) {
             var text = text[0];
-            if (this._state.searchText !== text) {
+            if ((text && this._state.searchText !== text) || (!text && this._state.newSearchText)) {
                 this._state.newSearchText = text;
                 this._lastInputChange = (new Date());
                 if (this._searchTimer === undefined) {
@@ -136,7 +136,11 @@ define([
                         if ((new Date()) - me._lastInputChange < 400) return;
 
                         me._state.searchText = me._state.newSearchText;
-                        (me._state.newSearchText !== '') && me.onQuerySearch();
+                        if (me._state.newSearchText !== '') {
+                            me.onQuerySearch();
+                        } else {
+                            me.api.asc_endFindText();
+                        }
                         clearInterval(me._searchTimer);
                         me._searchTimer = undefined;
                     }, 10);
diff --git a/apps/documenteditor/main/app/controller/LeftMenu.js b/apps/documenteditor/main/app/controller/LeftMenu.js
index 1a9e70001..956af1bed 100644
--- a/apps/documenteditor/main/app/controller/LeftMenu.js
+++ b/apps/documenteditor/main/app/controller/LeftMenu.js
@@ -293,6 +293,9 @@ define([
                     }
                 })).show();
                 break;
+            case 'help':
+                close_menu = !!isopts;
+                break;
             default: close_menu = false;
             }
 
diff --git a/apps/documenteditor/main/app/view/FileMenu.js b/apps/documenteditor/main/app/view/FileMenu.js
index 0b23ce8e1..8d1f840f5 100644
--- a/apps/documenteditor/main/app/view/FileMenu.js
+++ b/apps/documenteditor/main/app/view/FileMenu.js
@@ -66,6 +66,14 @@ define([
                     var item = _.findWhere(this.items, {el: event.currentTarget});
                     if (item) {
                         var panel = this.panels[item.options.action];
+                        if (item.options.action === 'help') {
+                            if ( panel.usedHelpCenter === true && navigator.onLine ) {
+                                this.fireEvent('item:click', [this, item.options.action, true]);
+                                window.open(panel.urlHelpCenter, '_blank');
+                                return;
+                            }
+                        }
+
                         this.fireEvent('item:click', [this, item.options.action, !!panel]);
 
                         if (panel) {
diff --git a/apps/documenteditor/main/app/view/FileMenuPanels.js b/apps/documenteditor/main/app/view/FileMenuPanels.js
index 46f03cfca..7c5689823 100644
--- a/apps/documenteditor/main/app/view/FileMenuPanels.js
+++ b/apps/documenteditor/main/app/view/FileMenuPanels.js
@@ -1989,6 +1989,7 @@ define([
             this.menu = options.menu;
             this.urlPref = 'resources/help/{{DEFAULT_LANG}}/';
             this.openUrl = null;
+            this.urlHelpCenter = '{{HELP_CENTER_WEB_EDITORS}}';
 
             this.en_data = [
                 {"src": "ProgramInterface/ProgramInterface.htm", "name": "Introducing Document Editor user interface", "headername": "Program Interface"},
@@ -2111,9 +2112,10 @@ define([
                             store.fetch(config);
                         } else {
                             if ( Common.Controllers.Desktop.isActive() ) {
-                                if ( store.contentLang === '{{DEFAULT_LANG}}' || !Common.Controllers.Desktop.helpUrl() )
+                                if ( store.contentLang === '{{DEFAULT_LANG}}' || !Common.Controllers.Desktop.helpUrl() ) {
+                                    me.usedHelpCenter = true;
                                     me.iFrame.src = '../../common/main/resources/help/download.html';
-                                else {
+                                } else {
                                     store.contentLang = store.contentLang === lang ? '{{DEFAULT_LANG}}' : lang;
                                     me.urlPref = Common.Controllers.Desktop.helpUrl() + '/' + store.contentLang + '/';
                                     store.url = me.urlPref + 'Contents.json';
diff --git a/apps/documenteditor/main/locale/en.json b/apps/documenteditor/main/locale/en.json
index e05ffd021..dbb9d862d 100644
--- a/apps/documenteditor/main/locale/en.json
+++ b/apps/documenteditor/main/locale/en.json
@@ -2077,6 +2077,7 @@
   "DE.Views.LeftMenu.tipSearch": "Search",
   "DE.Views.LeftMenu.tipSupport": "Feedback & Support",
   "DE.Views.LeftMenu.tipTitles": "Titles",
+  "DE.Views.LeftMenu.tipPageThumbnails": "Page Thumbnails",
   "DE.Views.LeftMenu.txtDeveloper": "DEVELOPER MODE",
   "DE.Views.LeftMenu.txtEditor": "Document Editor",
   "DE.Views.LeftMenu.txtLimit": "Limit Access",
diff --git a/build/Gruntfile.js b/build/Gruntfile.js
index f0ed31065..c4f166801 100644
--- a/build/Gruntfile.js
+++ b/build/Gruntfile.js
@@ -67,6 +67,9 @@ module.exports = function(grunt) {
                 }, {
                     from: /\{\{HELP_URL\}\}/g,
                     to: _encode(process.env.HELP_URL) || 'https://helpcenter.onlyoffice.com'
+                }, {
+                    from: /\{\{HELP_CENTER_WEB_EDITORS\}\}/g,
+                    to: _encode(process.env.HELP_CENTER_WEB_EDITORS) || 'https://helpcenter.onlyoffice.com/userguides/docs-index.aspx'
                 }, {
                     from: /\{\{DEFAULT_LANG\}\}/g,
                     to: _encode(process.env.DEFAULT_LANG) || 'en'