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

@mixin user-select($arg) {
  -webkit-user-select: $arg;
     -moz-user-select: $arg;
      -ms-user-select: $arg;
          user-select: $arg;
}

@mixin transition($args...) {
  -webkit-transition: $args;
  -moz-transition: $args;
  -ms-transition: $args;
  -o-transition: $args;
  transition: $args;
}

@mixin transition-delay($args...) {
  -webkit-transition-delay: $args;
  -moz-transition-delay: $args;
  -ms-transition-delay: $args;
  -o-transition-delay: $args;
  transition-delay: $args;
}

@mixin transform($args...) {
  -webkit-transform: $args;
  -moz-transform: $args;
  -ms-transform: $args;
  -o-transform: $args;
  transform: $args;
}

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

@mixin text-shadow($horizOffset, $vertOffset, $blur, $color) {
  -webkit-text-shadow: $horizOffset $vertOffset $blur $color;
  -moz-text-shadow: $horizOffset $vertOffset $blur $color;
  -ms-text-shadow: $horizOffset $vertOffset $blur $color; /* IE 10+ */
  -o-text-shadow: $horizOffset $vertOffset $blur $color;
  text-shadow: $horizOffset $vertOffset $blur $color;
}

@mixin opacity($opacity) {
  opacity: $opacity;
  $opacity-ie: $opacity * 100;
  filter: alpha(opacity=$opacity-ie); //IE8
}

@mixin grayscale($value) {
    -webkit-filter: grayscale($value);
    -moz-filter: grayscale($value);
    -ms-filter: grayscale($value);
    -o-filter: grayscale($value);
    filter: grayscale($value);
}

@mixin rgba-color($color, $background) {
  $percent: alpha($color) * 100%;
  $opaque: opacify($color, 1);
  $solid-color: mix($opaque, $background, $percent);
  background-color: $solid-color !important;
  background-color: $color !important;
}