A simple card background drawable for Android.

background_card.xml

<?xml version="1.0" encoding="utf-8"?>

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/background_card_selected" android:state_selected="true" />
    <item android:drawable="@drawable/background_card_selected" android:state_pressed="true" />
    <item android:drawable="@drawable/background_card_default" />
</selector>

background_card_default.xml

<?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="@color/card_shadow"></solid>
        </shape>
    </item>

    <item android:left="0dp" android:right="0dp" android:bottom="1dp">
        <shape android:shape="rectangle">
            <solid android:color="@color/card_background_default"></solid>
        </shape>
    </item>

</layer-list>

background_card_selected.xml

<?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="@color/card_shadow"></solid>
        </shape>
    </item>

    <item android:left="0dp" android:right="0dp" android:bottom="1dp">
        <shape android:shape="rectangle">
            <solid android:color="@color/card_background_selected"></solid>
        </shape>
    </item>

</layer-list>

colors.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="card_shadow">#8000</color>
    <color name="card_background_default">#F6F6F6</color>
    <color name="card_background_selected">#CCC</color>
</resources>