.container:not(#contents_message) {
  width: 100% !important;

  @media (min-width: 768px) {
    width: 750px !important;
  }

  @media (min-width: 992px) {
    width: 970px !important;
  }

  @media (min-width: 1200px) {
    width: 1170px !important;
  }
}

#contents_message {
  max-width: 100%;
}