Transparent background in web

[sebastianbuechler]

I wrapped my app as usual inside the device preview:

DevicePreview(
      backgroundColor: Colors.transparent,
      builder: ...
);

But when I build this to web target and embed it into an iFrame, I always see a white background around the device preview, and not a transparent background.

I used this to embed the iFrame:

<iframe src="http://localhost:55615/" allowtransparency="true" style="border: none;width: 100%;height: 500px;background:none transparent;"></iframe>

Example (see white space around device up to the light blue part):

Any ideas?