@media screen and (max-width: 36rem) {
  .navigation__secondary-autohide {
    transition-duration: .5s;
    transition-timing-function: cubic-bezier( 0.215, 0.610, 0.355, 1.000 );
    transition-property: transform;
    z-index: -1;
    position: relative;
    width: 100%;
  }

  .navigation__secondary-autohide--hidden {
    transform: translateY( -100% );
    width: 100%;
  }

  .navigation__secondary-autohide--nohide {
    height: 0;
  }
}

@media screen and (max-width: 36rem) {
  .navigation__secondary-autohide {
    transition-duration: .5s;
    transition-timing-function: cubic-bezier( 0.215, 0.610, 0.355, 1.000 );
    transition-property: transform;
    z-index: -1;
    position: relative;
    width: 100%;
  }

  .navigation__secondary-autohide--hidden {
    transform: translateY( -100% );
  }

  .navigation__secondary-autohide--nohide {
    height: 0;
  }
}

Remove duplicate width declaration in CSS
Remove duplicate width declaration in CSS