@mixin drop-shadow($left, $top, $blur, $color, $inset: false) {
  @if $inset {
    -webkit-box-shadow:inset $left $top $blur $color;
    -moz-box-shadow:inset $left $top $blur $color;
    box-shadow:inset $left $top $blur $color;
  } @else {
    -webkit-box-shadow: $left $top $blur $color;
    -moz-box-shadow: $left $top $blur $color;
    box-shadow: $left $top $blur $color;
  }
}
