<meta name=viewport content="width=device-width">
<style>
    body { font: -apple-system-body; }
</style>
<body>
    <h1>
        This is an H1 element with multiple lines of text.
    </h1>
    <div>
        This is body text spanning multiple lines. This is <span style="font-size: xx-large;">font-size xx-large spanning multiple lines.
        </span> This is body text spanning multiple lines. This is body text spanning multiple lines.<span style="font-size: 8px"> This is some text with 8px font size that spans multiple lines</span>. The rest of this text is back to apple system body.
        <span style="font-size: small">Finally some text that has fontsize small that spans multiple lines.</span>
    </div>
</body>
