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

<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    android:imeOptions="actionDone">

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/nav_host_fragment"
        android:name="androidx.navigation.fragment.NavHostFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true"
        app:defaultNavHost="true"
        app:navGraph="@navigation/nav_graph" />

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/bottom_navigation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:background="@drawable/bottom_nav_shape"
        android:elevation="2dp"
        android:visibility="gone"
        app:itemIconTint="@drawable/bottom_nav_selector"
        app:labelVisibilityMode="unlabeled"
        app:layout_behavior="@string/hide_bottom_view_on_scroll_behavior"
        app:layout_scrollFlags="scroll|enterAlways|snap"
        app:menu="@menu/bottom_nav_menu">

        <LinearLayout
            android:id="@+id/offline_mode_linear_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@color/colorAccent"
            android:layout_gravity="bottom"
            android:gravity="center"
            android:visibility="gone">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:textColor="@android:color/white"
                android:textSize="6dp"
                android:text="Offline mode"/>
        </LinearLayout>
    </com.google.android.material.bottomnavigation.BottomNavigationView>
</androidx.coordinatorlayout.widget.CoordinatorLayout>