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

  :-moz-placeholder {
    @content;
  }

  ::-moz-placeholder {
    @content;
  }

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

@mixin keyframes($name) {
  @-webkit-keyframes #{$name} {
    @content;
  }

  @-moz-keyframes #{$name} {
    @content;
  }

  @-ms-keyframes #{$name} {
    @content;
  }

  @keyframes #{$name} {
    @content;
  }
}