Fuel login page behavior on window shrink

[Kyrylo Romanenko]

We have two issues with shrinking of login page.
By default login login-box and login-fields-box are centered on page and this is expected behavior .

If window is shrinked for some extent - then login-box looses it`s centering: login-box appears displaced to right side of page and horizontal scrollbar appears. (Screenshot 1)

If window is shrinked even more - then login-box stretches to the right out from the window. (Screenshot 2)

Browsers: recent Chrome, Firefox, Internet Explorer 11 (except scrollbar appearance).

VERSION:
  feature_groups:
    - mirantis
  production: "docker"
  release: "7.0"
  openstack_version: "2015.1.0-7.0"
  api: "1.0"
  build_number: "288"
  build_id: "288"
  nailgun_sha: "93477f9b42c5a5e0506248659f40bebc9ac23943"
  python-fuelclient_sha: "1ce8ecd8beb640f2f62f73435f4e18d1469979ac"
  fuel-agent_sha: "082a47bf014002e515001be05f99040437281a2d"
  fuel-nailgun-agent_sha: "d7027952870a35db8dc52f185bb1158cdd3d1ebd"
  astute_sha: "a717657232721a7fafc67ff5e1c696c9dbeb0b95"
  fuel-library_sha: "121016a09b0e889994118aa3ea42fa67eabb8f25"
  fuel-ostf_sha: "1f08e6e71021179b9881a824d9c999957fcc7045"
  fuelmain_sha: "6b83d6a6a75bf7bca3177fcf63b2eebbf1ad0a85"