css实现圆圈波动

<div class="circle" style="display: inline-block;position: relative;">
    <div class="wave0 wave"></div>
    <div class="wave1 wave"></div>
    <div class="wave2 wave"></div>
    <div class="wave3 wave"></div>
    <div class="wave4 wave"></div> 
</div>

.circle{
        position: relative;
    /* margin: 0 auto; */
/*    left: 40%;
    bottom: 20px;*/
}
.wave{
    position:absolute;
    border-radius: 100%;
    top:calc((100% - 50px)/2);
    left:calc((100% - 50px)/2);
     width: 50px;
    height: 50px;
}
.wave0{
   background:#ffffff;
    border:1px solid black;
    z-index: 2
    -webkit-animation: sk-scaleout 2s infinite ease-in-out;
    animation: sk-scaleout 2s infinite ease-in-out;
    animation-delay:2s;
}
.wave1{
  background:#aeaeae;
  border:1px solid black;
  z-index:3;
  -webkit-animation: sk-scaleout 2s infinite ease-in-out;
  animation: sk-scaleout 2s infinite ease-in-out;
  animation-delay:2s;
}
.wave2{
  background:#ffffff;
  border:1px solid black;
  z-index:4;
  -webkit-animation: sk-scaleout 4s infinite ease-in-out;
    animation: sk-scaleout 4s infinite ease-in-out;
    animation-delay:2s;
}
.wave3{
  background:#4d4d4d;
  border:1px solid black;
  z-index:5;
  -webkit-animation: sk-scaleout 6s infinite ease-in-out;
    animation: sk-scaleout 6s infinite ease-in-out;
    animation-delay:2s;
}
.wave4{
  background:#3c3c3c;
  border:1px solid black;
  z-index:6;
  -webkit-animation: sk-scaleout 8s infinite ease-in-out;
    animation: sk-scaleout 8s infinite ease-in-out;
    animation-delay:2s;
}