.crt {
  position: relative;
}

.crt::before {
  width: 250px;
  margin: auto;
  content: " ";
  display: block;
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  background:
    linear-gradient(rgba(18, 16, 16, 0) 50%, rgba(0, 0, 0, 0.25) 50%),
    linear-gradient(
      90deg,
      rgba(255, 0, 0, 0.06),
      rgba(0, 255, 0, 0.02),
      rgba(0, 0, 255, 0.06)
    );
  z-index: 2;
  background-size:
    100% 2px,
    3px 100%;
  pointer-events: none;
}

@keyframes flicker {
  0% {
    opacity: 0.27861;
  }
  5% {
    opacity: 0.54769;
  }
  10% {
    opacity: 0.23604;
  }
  15% {
    opacity: 0.10626;
  }
  20% {
    opacity: 0.18128;
  }
  25% {
    opacity: 0.10626;
  }
  30% {
    opacity: 0.18128;
  }
  35% {
    opacity: 0.23604;
  }
}

.crt::after {
  content: " ";
  display: block;
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  background: rgba(18, 16, 16, 0.1);
  opacity: 0;
  z-index: 2;
  pointer-events: none;
  animation: flicker 0.15s infinite;
}