diff --git a/.nvmrc b/.nvmrc
deleted file mode 100644
index b009dfb9d9..0000000000
--- a/.nvmrc
+++ /dev/null
@@ -1 +0,0 @@
-lts/*
diff --git a/src/documentViewer/ipc.ts b/src/documentViewer/ipc.ts
new file mode 100644
index 0000000000..07b049b744
--- /dev/null
+++ b/src/documentViewer/ipc.ts
@@ -0,0 +1,29 @@
+import { handle } from '../ipc/main';
+import { SERVER_DOCUMENT_VIEWER_OPEN_URL } from '../servers/actions';
+import { dispatch, select } from '../store';
+
+export const startDocumentViewerHandler = (): void => {
+  handle(
+    'document-viewer/open-window',
+    async (event, url, _format, _options) => {
+      const validUrl = new URL(url);
+      const allowedProtocols = ['http:', 'https:'];
+      if (!allowedProtocols.includes(validUrl.protocol)) {
+        return;
+      }
+      const server = select(({ servers }) =>
+        servers.find(
+          (s) => new URL(s.url).origin === new URL(event.getURL()).origin
+        )
+      );
+      if (!server) {
+        return;
+      }
+
+      dispatch({
+        type: SERVER_DOCUMENT_VIEWER_OPEN_URL,
+        payload: { server: server.url, documentUrl: url },
+      });
+    }
+  );
+};
diff --git a/src/injected.ts b/src/injected.ts
index 613d210739..6cd8d93d78 100644
--- a/src/injected.ts
+++ b/src/injected.ts
@@ -202,6 +202,21 @@ const start = async () => {
     window.RocketChatDesktop.setGitCommitHash(gitCommitHash);
   });
 
+  Tracker.autorun(() => {
+    const uid = Meteor.userId();
+    if (!uid) return;
+    const themeAppearance: string = getUserPreference(uid, 'themeAppearence');
+    if (
+      ['dark', 'light', 'auto', 'high-contrast'].includes(
+        themeAppearance as any
+      )
+    ) {
+      window.RocketChatDesktop.setUserThemeAppearance(
+        themeAppearance as 'auto' | 'dark' | 'light' | 'high-contrast'
+      );
+    }
+  });
+
   Tracker.autorun(() => {
     const uid = Meteor.userId();
     if (!uid) return;
diff --git a/src/ipc/channels.ts b/src/ipc/channels.ts
index 0c978177ef..13a4017be9 100644
--- a/src/ipc/channels.ts
+++ b/src/ipc/channels.ts
@@ -41,6 +41,11 @@ type ChannelToArgsMap = {
   'outlook-calendar/has-credentials': () => Promise<boolean>;
   'outlook-calendar/clear-credentials': () => void;
   'outlook-calendar/set-user-token': (token: string, userId: string) => void;
+  'document-viewer/open-window': (
+    url: string,
+    format: string,
+    options: any
+  ) => void;
 };
 
 export type Channel = keyof ChannelToArgsMap;
diff --git a/src/main.ts b/src/main.ts
index 1c73801e53..8bb26c6d0b 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -8,6 +8,7 @@ import {
 } from './app/main/data';
 import { setUserDataDirectory } from './app/main/dev';
 import { setupDeepLinks, processDeepLinksInArgs } from './deepLinks/main';
+import { startDocumentViewerHandler } from './documentViewer/ipc';
 import { setupDownloads } from './downloads/main';
 import { setupMainErrorHandling } from './errors';
 import i18n from './i18n/main';
@@ -98,6 +99,7 @@ const start = async (): Promise<void> => {
   handleJitsiDesktopCapturerGetSources();
   handleDesktopCapturerGetSources();
   startOutlookCalendarUrlHandler();
+  startDocumentViewerHandler();
   checkSupportedVersionServers();
 
   await processDeepLinksInArgs();
diff --git a/src/preload.ts b/src/preload.ts
index d562a3d7b7..46e88c78bc 100644
--- a/src/preload.ts
+++ b/src/preload.ts
@@ -24,6 +24,7 @@ declare global {
 }
 
 contextBridge.exposeInMainWorld('JitsiMeetElectron', JitsiMeetElectron);
+contextBridge.exposeInMainWorld('RocketChatDesktop', RocketChatDesktop);
 
 const start = async (): Promise<void> => {
   console.log('[Rocket.Chat Desktop] preload.ts start');
@@ -36,8 +37,6 @@ const start = async (): Promise<void> => {
 
   window.removeEventListener('load', start);
 
-  contextBridge.exposeInMainWorld('RocketChatDesktop', RocketChatDesktop);
-
   setServerUrl(serverUrl);
 
   await whenReady();
diff --git a/src/servers/actions.ts b/src/servers/actions.ts
index bbf75e1658..feb497760f 100644
--- a/src/servers/actions.ts
+++ b/src/servers/actions.ts
@@ -4,6 +4,8 @@ export const SERVERS_LOADED = 'servers/loaded';
 export const SERVER_URL_RESOLUTION_REQUESTED =
   'server/url-resolution-requested';
 export const SERVER_URL_RESOLVED = 'server/url-resolved';
+export const SERVER_DOCUMENT_VIEWER_OPEN_URL =
+  'server/document-viewer/open-url';
 
 export type ServersActionTypeToPayloadMap = {
   [SERVERS_LOADED]: {
@@ -12,4 +14,8 @@ export type ServersActionTypeToPayloadMap = {
   };
   [SERVER_URL_RESOLUTION_REQUESTED]: Server['url'];
   [SERVER_URL_RESOLVED]: ServerUrlResolutionResult;
+  [SERVER_DOCUMENT_VIEWER_OPEN_URL]: {
+    server: Server['url'];
+    documentUrl: string;
+  };
 };
diff --git a/src/servers/common.ts b/src/servers/common.ts
index bc563a8f8a..c7fd698e0b 100644
--- a/src/servers/common.ts
+++ b/src/servers/common.ts
@@ -25,6 +25,8 @@ export type Server = {
   supportedVersionsSource?: 'server' | 'cloud' | 'builtin';
   supportedVersions?: SupportedVersions;
   expirationMessageLastTimeShown?: Date;
+  documentViewerOpenUrl?: string;
+  themeAppearance?: 'dark' | 'light' | 'auto' | 'high-contrast';
 };
 
 export const enum ServerUrlResolutionStatus {
diff --git a/src/servers/preload/api.ts b/src/servers/preload/api.ts
index cabf221dc8..03b0209a69 100644
--- a/src/servers/preload/api.ts
+++ b/src/servers/preload/api.ts
@@ -14,6 +14,7 @@ import { setUserPresenceDetection } from '../../userPresence/preload';
 import type { Server } from '../common';
 import { setBadge } from './badge';
 import { writeTextToClipboard } from './clipboard';
+import { openDocumentViewer } from './documentViewer';
 import { setFavicon } from './favicon';
 import { setGitCommitHash } from './gitCommitHash';
 import type { videoCallWindowOptions } from './internalVideoChatWindow';
@@ -26,6 +27,7 @@ import {
   setServerVersionToSidebar,
   setSidebarCustomTheme,
 } from './sidebar';
+import { setUserThemeAppearance } from './themeAppearance';
 import { setTitle } from './title';
 import { setUrlResolver } from './urls';
 import { setUserLoggedIn } from './userLoggedIn';
@@ -52,6 +54,7 @@ export type RocketChatDesktopAPI = {
     idleThreshold: number | null;
     setUserOnline: (online: boolean) => void;
   }) => void;
+  setUserThemeAppearance: (themeAppearance: Server['themeAppearance']) => void;
   createNotification: (
     options: NotificationOptions & {
       canReply?: boolean;
@@ -72,6 +75,7 @@ export type RocketChatDesktopAPI = {
   hasOutlookCredentials: () => Promise<boolean>;
   clearOutlookCredentials: () => void;
   setUserToken: (token: string, userId: string) => void;
+  openDocumentViewer: (url: string, format: string, options: any) => void;
 };
 
 export const RocketChatDesktop: RocketChatDesktopAPI = {
@@ -93,6 +97,7 @@ export const RocketChatDesktop: RocketChatDesktopAPI = {
   setTitle,
   setUserPresenceDetection,
   setUserLoggedIn,
+  setUserThemeAppearance,
   createNotification,
   destroyNotification,
   getInternalVideoChatWindowEnabled,
@@ -105,4 +110,5 @@ export const RocketChatDesktop: RocketChatDesktopAPI = {
   clearOutlookCredentials,
   setUserToken,
   setSidebarCustomTheme,
+  openDocumentViewer,
 };
diff --git a/src/servers/preload/documentViewer.ts b/src/servers/preload/documentViewer.ts
new file mode 100644
index 0000000000..1f43464bb6
--- /dev/null
+++ b/src/servers/preload/documentViewer.ts
@@ -0,0 +1,9 @@
+import { ipcRenderer } from 'electron';
+
+export const openDocumentViewer = (
+  url: string,
+  format: string,
+  options: any
+): void => {
+  ipcRenderer.invoke('document-viewer/open-window', url, format, options);
+};
diff --git a/src/servers/preload/themeAppearance.ts b/src/servers/preload/themeAppearance.ts
new file mode 100644
index 0000000000..c9a6a864ce
--- /dev/null
+++ b/src/servers/preload/themeAppearance.ts
@@ -0,0 +1,16 @@
+import { dispatch } from '../../store';
+import { WEBVIEW_USER_THEME_APPEARANCE_CHANGED } from '../../ui/actions';
+import type { Server } from '../common';
+import { getServerUrl } from './urls';
+
+export const setUserThemeAppearance = (
+  themeAppearance: Server['themeAppearance']
+): void => {
+  dispatch({
+    type: WEBVIEW_USER_THEME_APPEARANCE_CHANGED,
+    payload: {
+      url: getServerUrl(),
+      themeAppearance,
+    },
+  });
+};
diff --git a/src/servers/reducers.ts b/src/servers/reducers.ts
index 97f0736ad3..33b9f69906 100644
--- a/src/servers/reducers.ts
+++ b/src/servers/reducers.ts
@@ -26,8 +26,9 @@ import {
   WEBVIEW_SERVER_VERSION_UPDATED,
   SUPPORTED_VERSION_DIALOG_DISMISS,
   WEBVIEW_SIDEBAR_CUSTOM_THEME_CHANGED,
+  WEBVIEW_USER_THEME_APPEARANCE_CHANGED,
 } from '../ui/actions';
-import { SERVERS_LOADED } from './actions';
+import { SERVERS_LOADED, SERVER_DOCUMENT_VIEWER_OPEN_URL } from './actions';
 import type { Server } from './common';
 
 const ensureUrlFormat = (serverUrl: string | null): string => {
@@ -63,7 +64,9 @@ type ServersActionTypes =
   | ActionOf<typeof WEBVIEW_SERVER_UNIQUE_ID_UPDATED>
   | ActionOf<typeof WEBVIEW_SERVER_IS_SUPPORTED_VERSION>
   | ActionOf<typeof WEBVIEW_SERVER_VERSION_UPDATED>
-  | ActionOf<typeof SUPPORTED_VERSION_DIALOG_DISMISS>;
+  | ActionOf<typeof SUPPORTED_VERSION_DIALOG_DISMISS>
+  | ActionOf<typeof SERVER_DOCUMENT_VIEWER_OPEN_URL>
+  | ActionOf<typeof WEBVIEW_USER_THEME_APPEARANCE_CHANGED>;
 
 const upsert = (state: Server[], server: Server): Server[] => {
   const index = state.findIndex(({ url }) => url === server.url);
@@ -136,6 +139,11 @@ export const servers: Reducer<Server[], ServersActionTypes> = (
       return upsert(state, { url, uniqueID });
     }
 
+    case WEBVIEW_USER_THEME_APPEARANCE_CHANGED: {
+      const { url, themeAppearance } = action.payload;
+      return upsert(state, { url, themeAppearance });
+    }
+
     case WEBVIEW_SERVER_IS_SUPPORTED_VERSION: {
       const { url, isSupportedVersion } = action.payload;
       return upsert(state, { url, isSupportedVersion });
@@ -206,7 +214,7 @@ export const servers: Reducer<Server[], ServersActionTypes> = (
 
     case SERVERS_LOADED: {
       const { servers = state } = action.payload;
-      return servers.map((server) => ({
+      return servers.map((server: Server) => ({
         ...server,
         url: ensureUrlFormat(server.url),
       }));
@@ -214,9 +222,10 @@ export const servers: Reducer<Server[], ServersActionTypes> = (
 
     case APP_SETTINGS_LOADED: {
       const { servers = state } = action.payload;
-      return servers.map((server) => ({
+      return servers.map((server: Server) => ({
         ...server,
         url: ensureUrlFormat(server.url),
+        documentViewerOpenUrl: '',
       }));
     }
 
@@ -235,6 +244,11 @@ export const servers: Reducer<Server[], ServersActionTypes> = (
       return upsert(state, { url, outlookCredentials });
     }
 
+    case SERVER_DOCUMENT_VIEWER_OPEN_URL: {
+      const { server, documentUrl } = action.payload;
+      return upsert(state, { url: server, documentViewerOpenUrl: documentUrl });
+    }
+
     default:
       return state;
   }
diff --git a/src/ui/actions.ts b/src/ui/actions.ts
index 49a58a9abf..cefcbcba5d 100644
--- a/src/ui/actions.ts
+++ b/src/ui/actions.ts
@@ -65,6 +65,8 @@ export const WEBVIEW_GIT_COMMIT_HASH_CHECK = 'webview/git-commit-hash-check';
 export const WEBVIEW_TITLE_CHANGED = 'webview/title-changed';
 export const WEBVIEW_UNREAD_CHANGED = 'webview/unread-changed';
 export const WEBVIEW_USER_LOGGED_IN = 'webview/user-loggedin';
+export const WEBVIEW_USER_THEME_APPEARANCE_CHANGED =
+  'webview/user-theme-appearance-changed';
 export const WEBVIEW_ALLOWED_REDIRECTS_CHANGED =
   'webview/allowed-redirects-changed';
 export const SETTINGS_SET_REPORT_OPT_IN_CHANGED =
@@ -159,6 +161,10 @@ export type UiActionTypeToPayloadMap = {
     url: Server['url'];
     userLoggedIn: Server['userLoggedIn'];
   };
+  [WEBVIEW_USER_THEME_APPEARANCE_CHANGED]: {
+    url: Server['url'];
+    themeAppearance: Server['themeAppearance'];
+  };
   [WEBVIEW_GIT_COMMIT_HASH_CHECK]: {
     url: Server['url'];
     gitCommitHash: Server['gitCommitHash'];
diff --git a/src/ui/components/ServersView/DocumentViewer.tsx b/src/ui/components/ServersView/DocumentViewer.tsx
new file mode 100644
index 0000000000..4a0eb33f19
--- /dev/null
+++ b/src/ui/components/ServersView/DocumentViewer.tsx
@@ -0,0 +1,65 @@
+import { Box, IconButton } from '@rocket.chat/fuselage';
+import { useDarkMode } from '@rocket.chat/fuselage-hooks';
+
+const DocumentViewer = ({
+  url,
+  partition,
+  closeDocumentViewer,
+  themeAppearance,
+}: {
+  url: string;
+  partition: string;
+  themeAppearance: string | undefined;
+  closeDocumentViewer: () => void;
+}) => {
+  const theme = useDarkMode(
+    themeAppearance === 'auto' ? undefined : themeAppearance === 'dark'
+  )
+    ? 'dark'
+    : 'light';
+  return (
+    <>
+      <Box
+        bg={theme}
+        width='100%'
+        height='100%'
+        position='absolute'
+        content='center'
+        alignItems='center'
+      >
+        <Box
+          content='center'
+          alignItems='center'
+          display='flex'
+          color={theme === 'dark' ? 'font-white' : 'font-text'}
+        >
+          <IconButton
+            icon='arrow-back'
+            onClick={closeDocumentViewer}
+            mi='x8'
+            color={theme === 'dark' ? 'white' : 'default'}
+          />
+          <h2>PDF Viewer</h2>
+        </Box>
+
+        <Box>
+          <webview
+            src={url}
+            style={{
+              width: '100%',
+              height: '100%',
+              position: 'absolute',
+              left: 0,
+              top: 50,
+              right: 0,
+              bottom: 0,
+            }}
+            partition={partition}
+          />
+        </Box>
+      </Box>
+    </>
+  );
+};
+
+export default DocumentViewer;
diff --git a/src/ui/components/ServersView/ServerPane.tsx b/src/ui/components/ServersView/ServerPane.tsx
index 0b21da49ce..d2dbacfa36 100644
--- a/src/ui/components/ServersView/ServerPane.tsx
+++ b/src/ui/components/ServersView/ServerPane.tsx
@@ -1,17 +1,19 @@
 import { ipcRenderer } from 'electron';
-import { useRef, useEffect } from 'react';
+import { useRef, useEffect, useState } from 'react';
 import { useDispatch } from 'react-redux';
 import type { Dispatch } from 'redux';
 
+import { SERVER_DOCUMENT_VIEWER_OPEN_URL } from '../../../servers/actions';
 import type { RootAction } from '../../../store/actions';
 import {
   LOADING_ERROR_VIEW_RELOAD_SERVER_CLICKED,
   WEBVIEW_ATTACHED,
   WEBVIEW_READY,
 } from '../../actions';
+import DocumentViewer from './DocumentViewer';
 import ErrorView from './ErrorView';
 import UnsupportedServer from './UnsupportedServer';
-import { StyledWebView, Wrapper } from './styles';
+import { DocumentViewerWrapper, StyledWebView, Wrapper } from './styles';
 
 type ServerPaneProps = {
   lastPath: string | undefined;
@@ -20,6 +22,8 @@ type ServerPaneProps = {
   isFailed: boolean;
   isSupported: boolean | undefined;
   title: string | undefined;
+  documentViewerOpenUrl: string | undefined;
+  themeAppearance: string | undefined;
 };
 
 export const ServerPane = ({
@@ -28,9 +32,13 @@ export const ServerPane = ({
   isSelected,
   isFailed,
   isSupported,
+  documentViewerOpenUrl,
+  themeAppearance,
 }: ServerPaneProps) => {
   const dispatch = useDispatch<Dispatch<RootAction>>();
 
+  const [documentViewerActive, setDocumentViewerActive] = useState(false);
+
   const webviewRef =
     useRef<ReturnType<(typeof document)['createElement']>>(null);
 
@@ -137,6 +145,19 @@ export const ServerPane = ({
     }
   }, [lastPath, serverUrl]);
 
+  useEffect(() => {
+    const webview = webviewRef.current;
+    if (!webview) {
+      return;
+    }
+
+    if (isSelected && documentViewerOpenUrl && documentViewerOpenUrl !== '') {
+      setDocumentViewerActive(true);
+    } else {
+      setDocumentViewerActive(false);
+    }
+  }, [documentViewerOpenUrl, isSelected]);
+
   const handleReload = (): void => {
     dispatch({
       type: LOADING_ERROR_VIEW_RELOAD_SERVER_CLICKED,
@@ -153,8 +174,17 @@ export const ServerPane = ({
     } else {
       webview?.blur();
     }
+    // setDocumentViewerActive(true);
   }, [isSelected]);
 
+  const closeDocumentViewer = () => {
+    dispatch({
+      type: SERVER_DOCUMENT_VIEWER_OPEN_URL,
+      payload: { server: serverUrl, documentUrl: '' },
+    });
+    setDocumentViewerActive(false);
+  };
+
   useEffect(() => {
     const handleOnline = () => {
       ipcRenderer.invoke('refresh-supported-versions', serverUrl);
@@ -175,6 +205,14 @@ export const ServerPane = ({
         partition={`persist:${serverUrl}`}
         {...({ allowpopups: 'allowpopups' } as any)}
       />{' '}
+      <DocumentViewerWrapper isVisible={documentViewerActive}>
+        <DocumentViewer
+          url={documentViewerOpenUrl || ''}
+          partition={`persist:${serverUrl}`}
+          closeDocumentViewer={closeDocumentViewer}
+          themeAppearance={themeAppearance}
+        />
+      </DocumentViewerWrapper>
       <UnsupportedServer
         isSupported={isSupported}
         instanceDomain={new URL(serverUrl).hostname}
diff --git a/src/ui/components/ServersView/index.tsx b/src/ui/components/ServersView/index.tsx
index 1926579738..36b1ab15c7 100644
--- a/src/ui/components/ServersView/index.tsx
+++ b/src/ui/components/ServersView/index.tsx
@@ -16,6 +16,8 @@ export const ServersView = () => {
           isFailed={server.failed ?? false}
           isSupported={server.isSupportedVersion}
           title={server.title}
+          documentViewerOpenUrl={server.documentViewerOpenUrl}
+          themeAppearance={server.themeAppearance}
         />
       ))}
     </ReparentingContainer>
diff --git a/src/ui/components/ServersView/styles.tsx b/src/ui/components/ServersView/styles.tsx
index 63f04274b4..3ba5593e8d 100644
--- a/src/ui/components/ServersView/styles.tsx
+++ b/src/ui/components/ServersView/styles.tsx
@@ -18,6 +18,16 @@ export const Wrapper = styled.section<WrapperProps>`
   `};
 `;
 
+type DocumentViewerWrapperProps = {
+  isVisible: boolean;
+};
+
+export const DocumentViewerWrapper = styled.section<DocumentViewerWrapperProps>`
+  ${({ isVisible }) => css`
+    display: ${isVisible ? 'flex' : 'none'};
+  `};
+`;
+
 type StyledWebViewProps = {
   isFailed: boolean;
 };
diff --git a/src/ui/main/rootWindow.ts b/src/ui/main/rootWindow.ts
index 0e4225f92c..11ad6a4edb 100644
--- a/src/ui/main/rootWindow.ts
+++ b/src/ui/main/rootWindow.ts
@@ -394,7 +394,7 @@ export const showRootWindow = async (): Promise<void> => {
   }
 
   return new Promise((resolve) => {
-    browserWindow.addListener('ready-to-show', () => {
+    browserWindow.once('ready-to-show', () => {
       applyRootWindowState(browserWindow);
 
       const isTrayIconEnabled = select(
@@ -422,7 +422,7 @@ export const exportLocalStorage = async (): Promise<Record<string, string>> => {
     tempWindow.loadFile(path.join(app.getAppPath(), 'app/index.html'));
 
     await new Promise<void>((resolve) => {
-      tempWindow.addListener('ready-to-show', () => {
+      tempWindow.once('ready-to-show', () => {
         resolve();
       });
     });
diff --git a/src/ui/main/serverView/index.ts b/src/ui/main/serverView/index.ts
index 1c9cbc7f34..868f38d846 100644
--- a/src/ui/main/serverView/index.ts
+++ b/src/ui/main/serverView/index.ts
@@ -325,7 +325,6 @@ export const attachGuestWebContentsEvents = async (): Promise<void> => {
     guestWebContents.session.on(
       'will-download',
       (event, item, _webContents) => {
-        console.log('will-download', item);
         const fileName = item.getFilename();
         const extension = path.extname(fileName)?.slice(1).toLowerCase();
         const savePath = dialog.showSaveDialogSync(rootWindow, {