.bb, .bb::before, .bb::after {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
}

.bb {
  width: 200px;
  height: 200px;
  margin: auto;
  color: #28f4ff;
  background-color: rgba(5, 33, 78, 0.4);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.1);
}
.bb::before, .bb::after {
  content: '';
  z-index: -1;
  margin: -5%;
  box-shadow: inset 0 0 0 2px;
  animation: clipMe 8s linear infinite;
}
.bb::before {
  animation-delay: -4s;
}
.bb:hover::after, .bb:hover::before {
  background-color: rgba(255, 0, 0, 0.3);
}

@keyframes clipMe {
  0%, 100% {
  	clip: rect(0px, 220.0px, 2px, 0px);
  }
  25% {
 	 clip: rect(0px, 2px, 220.0px, 0px);
  }
  50% {
 	 clip: rect(218.0px, 220.0px, 220.0px, 0px);
  }
  75% {
 	 clip: rect(0px, 220.0px, 220.0px, 218.0px);
  }
}