above, you can define vector drawables, which scale without losing definition. You need only one asset file for a vector image, as opposed to an asset file for each screen density in the case of bitmap images. To create a vector image, you define the details of the shape inside a <vector> XML element." developer.android.com/training/material/drawables.html
name="MyTheme" parent="Theme.AppCompat.DayNight.NoActionBar"> <!-- Blah blah --> </style> MODE_NIGHT_NO: Sempre usa o “day” (light) theme; MODE_NIGHT_YES. Sempre usa o “night” (dark) theme; MODE_NIGHT_AUTO. Altera para day/night de acordo com a hora do dia; MODE_NIGHT_FOLLOW_SYSTEM (default). Vai seguir a configuração do sistema, que basicamente é MODE_NIGH_NO;