<!DOCTYPE html>
<iframe style="width: 300px; height: 300px"
srcdoc='<div style=" width: 100px; height: 200px; background: blue"></div>'
</iframe>
<!DOCTYPE html>
<iframe style="width: 300px; height: 300px"
srcdoc='<div style=" width: 100px; height: 200px; background: blue"></div>'
</iframe>