gistfile1.scss

$mobile = "screen and (min-width: 30em)";
$desktop = "screen and (min-width: 60em)";

$footer-height;

body{
  @media #{$mobile}{
    $footer-height: 200px; 
  }
  
  @media #{$desktop}{
    $footer-height: 350px;  
  }
}