Babylon.js/Viewer/assets/templates/default/defaultTemplate.html

<style>
    @font-face {
        font-family: 'babylon';
        src: url('{{babylonFont}}') format('woff');
        font-weight: normal;
        font-style: normal;
    }

    .icon {
        font-family: "babylon";
    }
</style>

<viewer></viewer>
<loading-screen></loading-screen>
<overlay></overlay>