activity_heavy_metals_details.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    tools:context="de.anna.cellfreestick.HeavyMetalsDetailsActivity" 
    android:background="#ff322f32" 
    style="@style/Base.Theme.AppCompat"> 
 
    <fragment 
        android:layout_width="match_parent" 
        android:layout_height="match_parent" 
        android:name="de.anna.cellfreestick.HeavyMetalsDetailsFragment" 
        android:id="@+id/fragment" 
        android:layout_centerVertical="true" 
        android:layout_centerHorizontal="true" 
        tools:layout="@layout/fragment_heavy_metals_details" /> 
</RelativeLayout>