.sk-wave {
  width: 30px;
  height: 27px;
}

.sk-wave > div {
  background-color: currentColor;
  height: 100%;
  width: 6px;
  display: inline-block;

  -webkit-animation: sk-stretchdelay 1.2s infinite ease-in-out;
  animation: sk-stretchdelay 1.2s infinite ease-in-out;
}

.sk-wave > div:nth-child(2) {
  -webkit-animation-delay: -1.1s;
  animation-delay: -1.1s;
}

.sk-wave > div:nth-child(3) {
  -webkit-animation-delay: -1.0s;
  animation-delay: -1.0s;
}

.sk-wave > div:nth-child(4) {
  -webkit-animation-delay: -0.9s;
  animation-delay: -0.9s;
}

.sk-wave > div:nth-child(5) {
  -webkit-animation-delay: -0.8s;
  animation-delay: -0.8s;
}

@-webkit-keyframes sk-stretchdelay {
  0%, 40%, 100% { -webkit-transform: scaleY(0.4) }
  20% { -webkit-transform: scaleY(1.0) }
}

@keyframes sk-stretchdelay {
  0%, 40%, 100% {
    transform: scaleY(0.4);
    -webkit-transform: scaleY(0.4);
  } 20% {
    transform: scaleY(1.0);
    -webkit-transform: scaleY(1.0);
  }
}