<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>

        <item name="android:actionBarStyle">@style/MyActionBar</item>

        <!-- Support library compatibility -->
        <item name="actionBarStyle">@style/MyActionBar</item>
    </style>

    <!-- ActionBar styles -->
    <style name="MyActionBar"
        parent="@style/Widget.AppCompat.Light.ActionBar.Solid.Inverse">
        <item name="android:background">@color/purple</item>

        <!-- Support library compatibility -->
        <item name="background">@color/purple</item>
    </style>

    <style name="AppTheme.NoActionBar">
        <item name="windowActionBar">false</item>
        <item name="windowNoTitle">true</item>
    </style>

    <style name="PhotoGridLayout">
        <item name="android:drawSelectorOnTop">true</item>
        <item name="android:listSelector">@drawable/photogrid_list_selector</item>
    </style>

    <style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />

    <style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />

</resources>

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.DayNight">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>

        <item name="android:actionBarStyle">@style/MyActionBar</item>

        <!-- Support library compatibility -->
        <item name="actionBarStyle">@style/MyActionBar</item>
    </style>

    <!-- ActionBar styles -->
    <style name="MyActionBar"
        parent="@style/Widget.AppCompat.Light.ActionBar.Solid.Inverse">
        <item name="android:background">@color/purple</item>

        <!-- Support library compatibility -->
        <item name="background">@color/purple</item>
    </style>

    <style name="AppTheme.NoActionBar">
        <item name="windowActionBar">false</item>
        <item name="windowNoTitle">true</item>
    </style>

    <style name="PhotoGridLayout">
        <item name="android:drawSelectorOnTop">true</item>
        <item name="android:listSelector">@drawable/photogrid_list_selector</item>
    </style>

    <style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />

    <style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />

</resources>

Add initial dark mode support
Add initial dark mode support
