sass mixin collection

sass-mixin.scss

@mixin css3($property, $value) {
  @each $prefix in -webkit-, -moz-, -ms-, -o-, '' {
    #{$prefix}#{$property}: $value;
  }
}
.border_radius {
  @include css3(transition, 0.5s);
}


@mixin opacity($opacity) {
  opacity: $opacity;
  $opacityIE: $opacity * 100;
  filter: alpha(opacity=$opacityIE);
}

.box {
  @include opacity(0.5);
}