.a-dance {
  @include keyframes(dance) {
    0%,
    10%,
    20% {
      transform: rotateZ(10deg);
    }

    5%,
    15%,
    25% {
      transform: rotateZ(-10deg);
    }

    35%,
    60%,
    100% {
      transform: scale(1) rotateZ(0deg);
      box-shadow: inset 0 0 0 0 transparent;
    }

    40% {
      transform: scale(1.3);
      box-shadow: inset 0 0 0 0;
      box-shadow: inset 0 0 0 2px rgba(0, 0, 0, 0.1);
    }
  }

  @include show();
  @include animate(dance $dance-timing linear 1);
}