@mixin grid-container($props…) {

@if length($props) ==0 {
  @include u-margin-x(auto);
  @include u-maxw($theme-grid-container-max-width);
} @else {
  $props: nth($props, 1);
  $margin-x: append-important($props, auto);
  @include u-margin-x($margin-x);
  @include u-maxw($props);
}

@include add-responsive-site-margins;
@include this-border-box-sizing;

}