$break-small: 768px;
$break-medium: 992px;
$break-large: 1200px;

@mixin media($medias...) {
  $max: length($medias);
  $media: '';

  @for $i from 1 through $max {
    $media: nth($medias, $i);

    @if $media == xs {
      @media only screen and (max-width: $break-small) { @content; }
    }
    @else if $media == sm {
      @media only screen and (min-width: $break-small + 1) and (max-width: $break-medium - 1) { @content; }
    }
    @else if $media == md {
      @media only screen and (min-width: $break-medium) and (max-width: $break-large - 1) { @content; }
    }
    @else if $media == lg {
      @media only screen and (min-width: $break-large) { @content; }
    }
  }
}