Signal-Android/app/src/main/res/values/registration_styles.xml

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

    <style name="Signal.Text.Headline.Registration">
        <item name="android:textSize">@dimen/registration_headline_text</item>
        <item name="android:fontFamily">sans-serif-medium</item>
    </style>

    <style name="Signal.Text.Body.Registration">
        <item name="android:textSize">@dimen/registration_body_text</item>
    </style>

</resources>