@mixin vendor-prefixed-properties($property, $value) {
  -webkit-#{$property}: $value;
  -moz-#{$property}: $value;
  -ms-#{$property}: $value;
  -o-#{$property}: $value;
  $property: $value;
}

@mixin appearance($appearance) {
  @include vendor-prefixed-properties(appearance, $appearance);
}

@mixin appearance-none {
  @include appearance(none);
}

@mixin placeholder {
  &.placeholder { @content }
  &::placeholder { @content }
  &:-ms-input-placeholder { @content }
  &::-moz-placeholder { @content }
  &::-webkit-input-placeholder { @content }
}