Fixed header and tabs in Ionic DevApp


I’m pretty newbie with Ionic and Ionic DevApp.

I’ve made basic page for testing purpose, with ion-header, ion-content and ion-tabs one by one. Trying to test in with DevApp, but when I swipe page ion-header and ion-tabs is not fixed and go to up and down. Obviously I want to swap only content in the middle of the page, and header should be static.
Is this behavior only with DevApp and with built project everything will be fine. Or I should rewrite default styles?