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>