@keyframes screenglowpulse {
  0% {
    box-shadow: 0px 0px 20px #0f0;
  }
  100% {
    box-shadow: 0px 0px 15px #0f0;
  }
}

canvas {
  box-shadow: 0px 0px 15px #0f0;
  animation: screenglowpulse 0.75s infinite;
  animation-timing-function: linear;
}