Mindustry/android/res/values-v21/styles.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style name="ArcTheme" parent="android:Theme.Material.NoActionBar">
        <item name="android:windowBackground">@android:color/transparent</item>
        <item name="android:colorBackgroundCacheHint">@null</item>
        <item name="android:windowAnimationStyle">@android:style/Animation</item>
        <item name="android:windowNoTitle">true</item>
        <item name="android:windowContentOverlay">@null</item>
        <item name="android:windowFullscreen">true</item>
    </style>
</resources>