libpdfviewer/app/src/main/res/values-night/styles.xml

<resources xmlns:tools="http://schemas.android.com/tools">

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.Material3.DayNight.NoActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">#DEFFFFFF</item>
        <item name="android:statusBarColor">@android:color/transparent</item>
        <item name="android:navigationBarColor">@android:color/transparent</item>
        <item name="android:windowLightNavigationBar" tools:ignore="NewApi">false</item>
    </style>

    <style name="AppTheme.PopupOverlay" parent="ThemeOverlay.Material3.DynamicColors.Dark" />

</resources>