$phone: 'screen and (max-width: 640px)';
$tablet: 'screen and (min-width: 641px) and (max-width: 1007px)';
$tablet-and-up: 'screen and (min-width: 641px)';
$pocket: 'screen and (max-width: 1007px)';
$lap: 'screen and (min-width: 1008px) and (max-width: 1239px)';
$lap-and-up: 'screen and (min-width: 1008px)';
$desk: 'screen and (min-width: 1240px)';
$widescreen: 'screen and (min-width: 1500px)';

@mixin av-mq($alias) {
  @if $alias=='phone' {
    @media #{$phone} {
      @content;
    }
  }
  @else if $alias=='tablet' {
    @media #{$tablet} {
      @content;
    }
  }
  @else if $alias=='tablet-and-up' {
    @media #{$tablet-and-up} {
      @content;
    }
  }
  @else if $alias=='pocket' {
    @media #{$pocket} {
      @content;
    }
  }
  @else if $alias=='lap' {
    @media #{$lap} {
      @content;
    }
  }
  @else if $alias=='lap-and-up' {
    @media #{$lap-and-up} {
      @content;
    }
  }
  @else if $alias=='desk' {
    @media #{$desk} {
      @content;
    }
  }
  @else if $alias=='widescreen' {
    @media #{$widescreen} {
      @content;
    }
  }
}