HABpanel style on app problem

I just made a .css file to my HABpanel, which works fine on web browser, but in OpenHab mobile app it’s not showing. Is there a way to fix it?

Hey @JBr,
can you post screenshots of browser and app?

Hej @mueller-ma, thanks for reply.

Here’s screenshoot from google chrome on smartphone.

And here’s from OpenHAB app on smartphone.

Background file is loading, but css file not. Why?

I don’t think that we can do much about this. We’re just displaying a Android webview with the url hardcoded to HABPanel. The webview is part of Android. What Android version do you use?
Can you try to update Android or install/update https://play.google.com/store/apps/details?id=com.google.android.webview&hl=en_US ?