.master__box {
  position: relative;
  width: 400px;
  height: 400px;
  background: rgba(0,0,0,.1);
  border-radius: 50%;
  overflow: hidden;
}

.master__box::before {
  content: '';
  position: absolute;
  inset: -10px 140px;
  background: linear-gradient(315deg,#00973c,#87fd00);
  border-radius: 30%;
  transition: .5s;
  animation: animate 4s linear infinite;
}

.master__box:hover:before {
  inset: -20px 0px;
}

@keyframes animate {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

.master__box::after {
  content: '';
  position: absolute;
  inset: 6px;
  background: #fff;
  border-radius: 50%;
  z-index: 1;
}