How to use platform-ios and platform-cordova css classes?

ionic-v1
15

That doesn’t work for me.
I have this but it doesn’t work on the Ionic View App.
In the normal Webbrowser it does.

body.platform-ios ion-modal-view ion-content.tab-content {
    padding-top: 90px !important;
}

body.platform-ios ion-content.tab-content {
    padding-top: 45px !important;
}

Can someone help me?