Christmas Lights

CSS

.christmasLights {
  -webkit-animation: flash 2s step-start infinite;
          animation: flash 2s step-start infinite;
  border-image-repeat: round;
  border-image-slice: 50% 0;
  border-style: solid;
  width: 100%;
}

@-webkit-keyframes flash {
  0% {
    border-width: 100px 0 0;
  }
  50% {
    border-width: 0 0 100px;
  }
  100% {
    border-width: 100px 0 0;
  }
}

@keyframes flash {
  0% {
    border-width: 100px 0 0;
  }
  50% {
    border-width: 0 0 100px;
  }
  100% {
    border-width: 100px 0 0;
  }
}