fedilab-Android-App/app/src/main/res/drawable/card_border_black.xml

<?xml version="1.0" encoding="UTF-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="@color/transparent"/>

    <stroke android:width="1dp"
        android:color="@color/cardBorderBlack"
        />

    <corners android:bottomRightRadius="3dp" android:bottomLeftRadius="3dp"
        android:topLeftRadius="3dp" android:topRightRadius="3dp"/>
</shape>