@mixin border-radius($radius) {
  -moz-border-radius: $radius;
  -webkit-border-radius: $radius;
  -o-border-radius: $radius;
  -ms-border-radius: $radius;
  -khtml-border-radius: $radius;
  border-radius: $radius;
}

@mixin border-radius-multi($r1,$r2,$r3,$r4) {
  -moz-border-radius: $r1 $r2 $r3 $r4;
  -webkit-border-radius: $r1 $r2 $r3 $r4;
  -o-border-radius: $r1 $r2 $r3 $r4;
  -ms-border-radius: $r1 $r2 $r3 $r4;
  -khtml-border-radius: $r1 $r2 $r3 $r4;
  border-radius: $r1 $r2 $r3 $r4;
}

@mixin linear-gradient($color1, $color2) {
  background-image: -webkit-gradient(linear, left top, left bottom, from($color1), to($color2));
  background-image: -webkit-linear-gradient(top, $color1, $color2);
  background-image: -moz-linear-gradient(top, $color1, $color2);
  background-image: -o-linear-gradient(top, $color1, $color2);
  background-image: -ms-linear-gradient(top, $color1, $color2);
  background-image: linear-gradient(top, $color1, $color2);
  filter: progid:DXImageTransform.Microsoft.gradient(startColorStr='#{$color1}', EndColorStr='#{$color2}');
}