Android de fondo de tarjeta transparente
<android.support.v7.widget.CardView
xmlns:card_view="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/myCardView"
android:layout_width="match_parent"
android:layout_height="match_parent"
card_view:cardBackgroundColor="@android:color/transparent"
card_view:cardElevation="0dp">
Purple Team