@mixin border-radius($topleft: 0, $topright: 0, $bottomright: 0, $bottomleft: 0) {
  -webkit-border-radius: $topleft $topright $bottomright $bottomleft;
     -moz-border-radius: $topleft $topright $bottomright $bottomleft;
      -ms-border-radius: $topleft $topright $bottomright $bottomleft;
       -o-border-radius: $topleft $topright $bottomright $bottomleft;
          border-radius: $topleft $topright $bottomright $bottomleft;
}

@mixin box-shadow($value) {
    -webkit-box-shadow: $value;
       -moz-box-shadow: $value;
        -ms-box-shadow: $value;
         -o-box-shadow: $value;
            box-shadow: $value;
}

@mixin background($from, $to) {
    @if $to == $from {
        background: $to;
    } @else {
        background: $to;
        background: -webkit-gradient(linear, left top, left bottom, from($from), to($to));
        background: -moz-linear-gradient(top, $from, $to);
        background: -ms-linear-gradient(top, $from, $to);
        background: -o-linear-gradient(top, $from, $to);
        background: linear-gradient(to bottom, $from, $to);
        filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#{ie_hex_str($from)}', endColorstr='#{ie_hex_str($to)}');
    }
}