修改

app/src/main/res/layout/fragment_bookshelf1.xml

@@ -11,7 +11,9 @@
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:background="?attr/colorSurface"
-        android:fitsSystemWindows="true">
+        android:fitsSystemWindows="true"
+        app:liftOnScroll="false"
+        android:stateListAnimator="@null">
 
         <com.google.android.material.appbar.CollapsingToolbarLayout
             android:layout_width="match_parent"
@@ -19,6 +21,8 @@
             style="?attr/collapsingToolbarLayoutLargeSize"
             app:collapsedTitleTextAppearance="?attr/textAppearanceTitleLarge"
             app:expandedTitleTextAppearance="?attr/textAppearanceHeadlineLarge"
+            app:contentScrim="?attr/colorSurface"
+            app:titleCollapseMode="scale"
             app:layout_scrollFlags="scroll|exitUntilCollapsed|snap">
 
             <com.google.android.material.appbar.MaterialToolbar
@@ -34,9 +38,8 @@
             android:id="@+id/tab_layout"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:paddingStart="16dp"
             android:background="?attr/colorSurface"
-            tools:ignore="RtlSymmetry" />
+            android:paddingHorizontal="16dp"/>
     </com.google.android.material.appbar.AppBarLayout>
 
     <!-- ViewPager -->