Why is the status bar no longer transparent?

Question

Android

All the best. I'm testing the app on Android 6. Translucent status bar. Then I experiment with styles. Specifically, in the Preview window for the view, I selected a different theme at the top. I launch the application - the status bar turned black.
I do git reset --hard HEAD. Compile, run. Status bar - black. Here I do not understand 2 things:
1. How does the choice of theme in the preview window affect the design of the view? (when changing the theme, git does not see changes in styles, manifest)
2. Why after git reset the status of the bar did not become the same (translucent)?
I don’t understand how to work with styles, inheritances at all ... I can’t find intelligible literature ... If there is a worthy source, share it.

Answer 1

I answer. As always carelessness. From the git commits, I found that a couple of days ago I changed the targetSdkVersion from 24 to 15 ... and for 2 days I did not pay attention to the statusbar. Today I noticed that it is black. I thought that today it "broke"... targetSdkVersion 24 - and the statusbar became translucent again.