body {
  background: #000;
  color: #00ff88;
  font-family: 'Courier New', Courier, monospace;
  padding: 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
  flex-direction: column;
  overflow: hidden;
  animation: flicker 5s infinite alternate;
}
#ascii {
  white-space: pre;
  font-size: 10px;
  line-height: 1.2em;
  opacity: 1;
  transition: opacity 0.5s ease-in-out;
}
.visible {
  opacity: 1;
}
@keyframes flicker {
  0% { background-color: #000; }
  2% { background-color: #001a00; }
  4% { background-color: #000; }
  6% { background-color: #002200; }
  8% { background-color: #000; }
  10% { background-color: #001800; }
  100% { background-color: #000; }
}
.crt {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  pointer-events: none;
  background-image: repeating-linear-gradient(
    0deg,
    rgba(0, 255, 136, 0.02) 0px,
    rgba(0, 255, 136, 0.02) 1px,
    transparent 1px,
    transparent 2px
  );
  z-index: 1;
}
#ascii::after {
  content: '_';
  animation: blink 1s step-end infinite;
}
@keyframes blink {
  from, to { opacity: 0; }
  50% { opacity: 1; }
}