<div style="width: 100%; height: 100%;">
    <div style="margin: auto;width: 400px;margin-top: 100px;border: 1px solid #f0f0f0;border-radius: 5px;padding: 20px;">
        <h2>{title}</h2>
        <div style="font-size: 16px">{content}</div>
        <div style="text-align: center;font-size: 14px;margin-top: 100px;">
            <a href="{site_url}" target="_blank">{site_name}</a>
        </div>
    </div>
</div>