.placeholder(@color: @input-color-placeholder) {
  // Firefox
  &::-moz-placeholder {
    color: @color;
    opacity: 0.5; // See https://github.com/twbs/bootstrap/pull/11526
  }
  &:-ms-input-placeholder { color: @color; } // Internet Explorer 10+
  &::-webkit-input-placeholder  { color: @color; } // Safari and Chrome
}