increase tab page margin (#1684)

app/src/main/res/layout-sw640dp/fragment_timeline.xml

@@ -3,8 +3,8 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
-    android:background="?attr/windowBackgroundColor"
-    android:layout_height="match_parent">
+    android:layout_height="match_parent"
+    android:background="?attr/windowBackgroundColor">
 
     <androidx.constraintlayout.widget.ConstraintLayout
         android:layout_width="640dp"

app/src/main/res/layout/activity_main.xml

@@ -36,7 +36,7 @@
 
     <androidx.viewpager2.widget.ViewPager2
         android:id="@+id/pager"
-        android:background="?android:windowBackground"
+        android:background="?attr/windowBackgroundColor"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:layout_below="@id/tab_layout"

app/src/main/res/layout/fragment_timeline_notifications.xml

@@ -3,7 +3,8 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
-    android:layout_height="match_parent">
+    android:layout_height="match_parent"
+    android:background="?android:attr/colorBackground">
 
     <com.google.android.material.appbar.AppBarLayout
         android:id="@+id/appBarOptions"

app/src/main/res/values/dimens.xml

@@ -9,7 +9,7 @@
     <dimen name="compose_media_preview_size">120dp</dimen>
     <dimen name="compose_options_margin">8dp</dimen>
     <dimen name="account_avatar_margin">14dp</dimen>
-    <dimen name="tab_page_margin">8dp</dimen>
+    <dimen name="tab_page_margin">16dp</dimen>
     <dimen name="status_line_margin_start">36dp</dimen>
     <dimen name="text_content_margin">16dp</dimen>
     <dimen name="status_sensitive_media_button_padding">5dp</dimen>