set position to fixed for article container wrapper in /app routes

packages/web/components/templates/PrimaryLayout.tsx

@@ -1,6 +1,12 @@
 import { PageMetaData, PageMetaDataProps } from '../patterns/PageMetaData'
 import { Box } from '../elements/LayoutPrimitives'
-import { ReactNode, MutableRefObject, useEffect, useContext, useState } from 'react'
+import {
+  ReactNode,
+  MutableRefObject,
+  useEffect,
+  useContext,
+  useState,
+} from 'react'
 import { PrimaryHeader } from './../patterns/PrimaryHeader'
 import { useGetViewerQuery } from '../../lib/networking/queries/useGetViewerQuery'
 import { navigationCommands } from '../../lib/keyboardShortcuts/navigationShortcuts'
@@ -11,7 +17,6 @@ import { ConfirmationModal } from '../patterns/ConfirmationModal'
 import { KeyboardShortcutListModal } from './KeyboardShortcutListModal'
 import { logoutMutation } from '../../lib/networking/mutations/logoutMutation'
 
-
 type PrimaryLayoutProps = {
   children: ReactNode
   pageTestId: string
@@ -25,7 +30,8 @@ export function PrimaryLayout(props: PrimaryLayoutProps): JSX.Element {
   const { viewerData } = useGetViewerQuery()
   const router = useRouter()
   const [showLogoutConfirmation, setShowLogoutConfirmation] = useState(false)
-  const [showKeyboardCommandsModal, setShowKeyboardCommandsModal] = useState(false)
+  const [showKeyboardCommandsModal, setShowKeyboardCommandsModal] =
+    useState(false)
 
   useKeyboardShortcuts(navigationCommands(router))
 

packages/web/components/templates/article/Article.tsx

@@ -63,10 +63,12 @@ export function Article(props: ArticleProps): JSX.Element {
 
   // Post message to webkit so apple app embeds get progress updates
   useEffect(() => {
-    window?.webkit?.messageHandlers.readingProgressUpdate?.postMessage({
-      progress: debouncedReadingProgress,
-    })
-  }, [debouncedReadingProgress])
+    if (typeof window?.webkit != 'undefined') {
+      window.webkit.messageHandlers.readingProgressUpdate?.postMessage({
+        progress: debouncedReadingProgress,
+      })
+    }
+  }, [readingProgress, debouncedReadingProgress])
 
   const setScrollWatchedElement = useScrollWatcher(
     (changeset: ScrollOffsetChangeset) => {

packages/web/pages/app/[username]/[slug]/index.tsx

@@ -69,6 +69,7 @@ function AppArticleEmbedContent(
       <Box
         ref={scrollRef}
         css={{
+          position: 'fixed',
           overflowY: 'auto',
           height: '100%',
           width: '100vw',