@mixin square($property){ width: $property; height: $property; } @mixin user-select($select){ -moz-user-select: $select; -khtml-user-select: $select; -webkit-user-select: $select; -o-user-select: $select; user-select: $select; } @mixin border-shadow($top: $gray05, $bottom: $gray04){ border-top: 1px solid $top; border-bottom: 1px solid $bottom; } @mixin center($width, $height){ position: absolute; top: 50%; left: 50%; margin-left: $width/(-2); margin-top: $height/(-2); width: $width; height: $height; }