message: fix some page header styling for nav
diff: z-index: $zindex-page-header-nav
  @media $media-md-up
  - height: 65px
  + height: 63px
  // Force on to GPU.
  // For some reason Chrome wasn't repainting when it would disappear.
  &-controls
  clearfix()
  - margin-top: 14px
  + margin-top: 13px
  margin-bottom: $grid-gutter-width-xs
  @media $media-md-up
  