Мерцающий текст к Хэллоуину на CSS

Небольшой сниппет мерцающего текста , который можно использовать для украшения блога к празднику Хэллоуина. Мерцание выполнено при помощи CSS.

HTML

<div>
  <span id="I">H</span>
  <span id="T">A</span>
  <span id="I">L</span>
  <span id="T">L</span>
  <span id="I">🎃</span>
  <span id="T">W</span>
  <span id="I">E</span>
  <span id="T">E</span>
  <span id="I">N</span>
</div>

CSS

:root {
  --white:#f1f1f1
}
body {
  margin: 0;
  font-family: Montserrat;
  font-size: 40px;
  color: var(--white);
  letter-spacing: 0.7em;
  background-color: black;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}
div > span {
  opacity: 0.15;
}
#I {
  opacity: 1;
  animation: flickerI 2s linear  reverse infinite;
}
#I::after {
  content: '';
  width: 150%;
  -webkit-box-shadow: -35px 0px 60px 8px rgba(255,255,255,1);
  -moz-box-shadow: -35px 0px 60px 8px rgba(255,255,255,1);
  box-shadow: -35px 0px 60px 8px rgba(255,255,255,1);
}
#L, #G {
  animation: flickerLG 2s linear reverse infinite;
  position: relative;
}
#L::after, 
#L::before  {
  content:' ';
  width: 100px;
  height: 100px;
  background: var(--white);
  position: absolute;
  top: -50%;
  left: 100%;
  border-radius: 100%;
  opacity: 0.05;
  filter: blur(10px);
}
#L::after {
  width: 200px;
  height: 200px;
  top: -150%;
  left: -5%;
  opacity: 0.1;
  filter: blur(10px);
}
#H {
  animation: flickerH 2s linear reverse infinite
}

#T {
  animation: flickerH 2s linear reverse infinite
}

@keyframes flickerI {
  0% {
    opacity: 0.4;
  }
  5% {
    opacity: 0.5;
  }
  10% {
    opacity: 0.6;
  }
  15% {
    opacity: 0.85;
  }
  25% {
    opacity: 0.5;
  }
  30% {
    opacity: 1;
  }
  35% {
    opacity: 0.1;
  }
  40% {
    opacity: 0.25;
  }
  45% {
    opacity: 0.5;
  }
  60% {
    opacity: 1;
  }
  70% {
    opacity: 0.85;
  }
  80% {
    opacity: 0.4;
  }
  90% {
    opacity: 0.5;
  }
  100% {
    opacity: 1;
  }
}

@keyframes flickerLG {
  0% {
    opacity: 0.19;
  }
  5% {
    opacity: 0.2;
  }
  10% {
    opacity: 0.25;
  }
  15% {
    opacity: 0.35;
  }
  25% {
    opacity: 0.2;
  }
  30% {
    opacity: 0.4;
  }
  35% {
    opacity: 0.1;
  }
  40% {
    opacity: 0.25;
  }
  45% {
    opacity: 0.2;
  }
  60% {
    opacity: 0.4;
  }
  70% {
    opacity: 0.35;
  }
  80% {
    opacity: 0.4;
  }
  90% {
    opacity: 0.2;
  }
  100% {
    opacity: 0.4;
  }
}

@keyframes flickerH {
  0% {
    opacity: 0.15;
  }
  5% {
    opacity: 0.2;
  }
  10% {
    opacity: 0.12;
  }
  15% {
    opacity: 0.2;
  }
  25% {
    opacity: 0.15;
  }
  30% {
    opacity: 0.4;
  }
  35% {
    opacity: 0.05;
  }
  40% {
    opacity: 0.12;
  }
  45% {
    opacity: 0.15;
  }
  60% {
    opacity: 0.3;
  }
  70% {
    opacity: 0.2;
  }
  80% {
    opacity: 0.3;
  }
  90% {
    opacity: 0.18;
  }
  100% {
    opacity: 0.3;
  }
}

@keyframes flickerT {
  0% {
    opacity: 0.01;
  }
  5% {
    opacity: 0.05;
  }
  10% {
    opacity: 0.03;
  }
  15% {
    opacity: 0.1;
  }
  25% {
    opacity: 0.07;
  }
  30% {
    opacity: 0.1;
  }
  35% {
    opacity: 0.05;
  }
  40% {
    opacity: 0.06;
  }
  45% {
    opacity: 0.1;
  }
  60% {
    opacity: 0.;
  }
  70% {
    opacity: 0.1;
  }
  80% {
    opacity: 0.;
  }
  90% {
    opacity: 0.0;
  }
  100% {
    opacity: 0.1;
  }
}