@mixin transition($time) {
  -webkit-transition: all $time ease-in-out 0s;
  -moz-transition: all $time ease-in-out 0s;
  -ms-transition: all $time ease-in-out 0s;
  -o-transition: all $time ease-in-out 0s;
  transition: all $time ease-in-out 0s;
}

@mixin transform($value) {
  -webkit-transform: $value;
  -ms-transform: $value;
  transform: $value;
}

@function _rgba($color, $opacity: 1) {
  @return unquote("rgba(#{red($color)}, #{green($color)}, #{blue($color)}, #{$opacity})");
}

@mixin placeholder {
  &::-webkit-input-placeholder {
    @content;
  }

  &:-moz-placeholder {
    @content;
  }

  &::-moz-placeholder {
    @content;
  }

  &:-ms-input-placeholder {
    @content;
  }
}