.loading{
  width: 80px;
  height: 40px;
  margin: 0 auto;
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%,-50%);
  z-index: 99;
}
.loading span{
  display: inline-block;
  width: 8px;
  height: 100%;
  border-radius: 4px;
  background: lightgreen;
  -webkit-animation: load 1s ease infinite;
}
@-webkit-keyframes load{
  0%,100%{
      height: 40px;
      background: lightgreen;
  }
  50%{
      height: 70px;
      margin: -15px 0;
      background: lightblue;
  }
}
.loading span:nth-child(2){
  -webkit-animation-delay:0.2s;
}
.loading span:nth-child(3){
  -webkit-animation-delay:0.4s;
}
.loading span:nth-child(4){
  -webkit-animation-delay:0.6s;
}
.loading span:nth-child(5){
  -webkit-animation-delay:0.8s;
}