body{
  width: 100%;
  height:100vh;
  background-color: #fff;
}

.box{
  width: 200px;
  height: 200px;
  position: relative;
  top: 50%;
  left: 50%;
  -webkit-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
}

.wave{
  position: absolute;
  width: inherit;
  height: inherit;
  transform-origin: 50% 48%;
  border-radius: 43%;
  animation: rotation 3000ms infinite linear;
  opacity: .3;
  background: rgb(255,236,147);
  background: linear-gradient(39deg, rgba(255,236,147,1) 0%, rgba(18,221,251,1) 100%);
}

.wave:nth-of-type(2){
  animation: rotation 5000ms infinite linear;
  opacity: .2;
}

.wave:nth-of-type(3){
  animation: rotation 7000ms infinite linear;
  opacity: .2;
}
.txt{
  color: #fff;
  font-size: 18px;
  text-align: center;
  width: 100%;
  height: 18px;
  position: absolute;
  display: block;
  top: 0;
  bottom: 0;
  margin: auto;
  text-shadow: 0px 0px 20px #3091d0;
}
@keyframes rotation {
  0%{transform: rotate(0deg);}
  100%{transform: rotate(360deg);}
}