<!DOCTYPE html>
<meta charset=utf-8>
<style>
    @font-face {
        font-family: arial_black;
        font-weight: 900;
        src: local("Arial Black");
    }
    h1 {
        font-family: Arial;
        font-weight: bold;
    }
    /* We include an extra-large invisible character in the test line
       to ensure a consistent baseline; otherwise differing metrics
       between the various Arial faces can disrupt it. */
    x {
        font-family: Arial;
        font-size: 2em;
        color: transparent;
    }
</style>
<h1>bold العربي <b>bolder العربي</b><x>A</x></h1>