Create card_background.xml in the res/drawable folder with the following code:
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<shape android:shape="rectangle">
<solid android:color="#BDBDBD"/>
<corners android:radius="5dp"/>
</shape>
</item>
<item
android:left="0dp"
android:right="0dp"
android:top="0dp"
android:bottom="2dp">
<shape android:shape="rectangle">
<solid android:color="#ffffff"/>
<corners android:radius="5dp"/>
</shape>
</item>
</layer-list>
Then add the following code to the element to which you want the card layout
android:background="@drawable/card_background"
the following line defines the color of the shadow for the card
<solid android:color="#BDBDBD"/>