.neon {
  animation: flicker 2.5s infinite alternate;
  color: #fff;
}

h1 {
  font-size: 4.2rem;    
}

/* Flickering animation */
@keyframes flicker {
    
  0%, 18%, 22%, 25%, 53%, 57%, 100% {

      text-shadow:
      0 0 4px #F99494,
      0 0 11px #FF5A5A,
      0 0 19px #FF5A5A,
      0 0 40px #BD3737,
      0 0 80px #BD3737,
      0 0 90px #BD3737,
      0 0 100px #812424,
      0 0 150px #812424;
  
  }
  
  20%, 24%, 55% {        
      text-shadow: none;
  }    
}