<html>

<body>
    <center>
        <iframe src="./emu.html" width="240" height="160"></iframe>
    </center>
</body>

<style>
    iframe {
        width: min(100%, calc(100vh / (2/3)));
        height: min(100%, calc(100vw / (2/3)));
        border: 0;
    }
</style>

</html>