body {
  font: 15vw/1 Permanent Marker;
  display: -webkit-box;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-align: center;
  -webkit-align-items: center;
      -ms-flex-align: center;
          align-items: center;
  -webkit-box-pack: center;
  -webkit-justify-content: center;
      -ms-flex-pack: center;
          justify-content: center;
  height: 100vh;
  text-align: center;
  background: #111;
  color: snow;
}

span {
  -webkit-animation: glow 2s ease-in-out both infinite;
          animation: glow 2s ease-in-out both infinite;
}
span:nth-child(1) {
  -webkit-animation-delay: -0.28571s;
          animation-delay: -0.28571s;
}
span:nth-child(2) {
  -webkit-animation-delay: -0.57143s;
          animation-delay: -0.57143s;
}
span:nth-child(3) {
  -webkit-animation-delay: -0.85714s;
          animation-delay: -0.85714s;
}
span:nth-child(4) {
  -webkit-animation-delay: -1.14286s;
          animation-delay: -1.14286s;
}
span:nth-child(5) {
  -webkit-animation-delay: -1.42857s;
          animation-delay: -1.42857s;
}
span:nth-child(6) {
  -webkit-animation-delay: -1.71429s;
          animation-delay: -1.71429s;
}
span:nth-child(7) {
  -webkit-animation-delay: -2s;
          animation-delay: -2s;
}

@-webkit-keyframes glow {
  0%, 100% {
    text-shadow: 0 0 8.33333px snow, 0 -25px 50px tomato, -25px 25px 50px yellow, 25px 25px 50px tomato;
  }
  33% {
    text-shadow: 0 0 8.33333px snow, 0 -25px 50px cyan, -25px 25px 50px tomato, 25px 25px 50px cyan;
  }
  66% {
    text-shadow: 0 0 8.33333px snow, 0 -25px 50px yellow, -25px 25px 50px cyan, 25px 25px 50px yellow;
  }
}

@keyframes glow {
  0%, 100% {
    text-shadow: 0 0 8.33333px snow, 0 -25px 50px tomato, -25px 25px 50px yellow, 25px 25px 50px tomato;
  }
  33% {
    text-shadow: 0 0 8.33333px snow, 0 -25px 50px cyan, -25px 25px 50px tomato, 25px 25px 50px cyan;
  }
  66% {
    text-shadow: 0 0 8.33333px snow, 0 -25px 50px yellow, -25px 25px 50px cyan, 25px 25px 50px yellow;
  }
}