<div class="water"></div>
body {
  margin: 50px;
}

.water {
  margin: auto;
  position: relative;
  width: 200px;
  height: 200px;
  background-color: #80c5de;
  box-shadow: inset 0 0 50px #1c637c;
  clip-path: polygon(0 0, 100% 0, 85% 100%, 15% 100%)
}

.water::before {
  content: "";
  width: 200%;
  height: 200%;
  background-color: #ececec;
  position: absolute;
  top: -150%;
  left: -50%;
  border-radius: 40%;
  animation: anim 12s linear infinite;
}

.water::after {
  content: "";
  width: 204%;
  height: 204%;
  background-color: #ececec80;
  position: absolute;
  top: -150%;
  left: -52%;
  border-radius: 40%;
  animation: anim 12s linear infinite;
  animation-delay: 0.5s;
}

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

External CSS

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External JavaScript

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