<!DOCTYPE html>
<html>
<head>
<script>
if (window.internals)
    window.internals.settings.setShouldAllowDesignSystemUIFonts(true);
</script>
<style>
@font-face {
    font-family: "AppleSystemUISerif";
    src: local("-apple-system-ui-serif");
}
@font-face {
    font-family: "AppleSystemUIMonospaced";
    src: local("-apple-system-ui-monospaced");
}
@font-face {
    font-family: "AppleSystemUIRounded";
    src: local("-apple-system-ui-rounded");
}
@font-face {
    font-family: "DotAppleSystemUIFontSerif";
    src: local(".AppleSystemUIFontSerif");
}
@font-face {
    font-family: "DotSFNSMono";
    src: local(".SF NS Mono");
}
@font-face {
    font-family: "DotSFUIMono";
    src: local(".SF UI Mono");
}
@font-face {
    font-family: "DotAppleSystemUIFontRounded";
    src: local(".AppleSystemUIFontRounded");
}
</style>
</head>
<body>
This test makes sure that the design system UI fonts don't work unless the shouldAllowDesignSystemUIFonts preference is set. The test passes if all the text below is bold.
<div>
<div style="display: inline-block; font: bold 72px 'AppleSystemUISerif'; font-synthesis: none;">HeJllo</div>
<div style="display: inline-block; font: bold 72px 'AppleSystemUIMonospaced'; font-synthesis: none;">HeJllo</div>
<div style="display: inline-block; font: bold 72px 'AppleSystemUIRounded'; font-synthesis: none;">HeJllo</div>
<div style="display: inline-block; font: bold 72px 'DotAppleSystemUIFontSerif'; font-synthesis: none;">HeJllo</div>
<div style="display: inline-block; font: bold 72px 'DotSFNSMono'; font-synthesis: none;">HeJllo</div>
<div style="display: inline-block; font: bold 72px 'DotSFUIMono'; font-synthesis: none;">HeJllo</div>
<div style="display: inline-block; font: bold 72px 'DotAppleSystemUIFontRounded'; font-synthesis: none;">HeJllo</div>
</div>
</body>
</html>