Restore Wallet Modal: fix mobile view

[VitaliyShulik]

[Disti4ct]

seems it appers when you open the app as a new user (or if you cleaned browser data)

[VitaliyShulik]

it's happened because of when media-mobile:

.overlay {
    position: absolute;
  }

and

.header-mobile > div  { z-index: 9999999; }