<p class="effect">welcome</p>

body {font-family: tahoma;}
.effect {
  font-size: 70px;
  color: #fff;
  text-align: center;
  animation: effect 1s ease-in-out infinite alternate;
}

@-webkit-keyframes effect {
  from {
    text-shadow: 0 0 10px #fff, 0 0 20px #fff, 0 0 30px #960018, 0 0 40px #960018, 0 0 50px #960018, 0 0 60px #960018, 0 0 70px #960018;
  }
  
  to {
    text-shadow: 0 0 20px #fff, 0 0 30px red, 0 0 40px red, 0 0 50px red, 0 0 60px red, 0 0 70px red, 0 0 80px red;
  }
}

<iframe src="https://www.netbax.net/tab/creation/neon.html" style="width: 550px; height:550px;" frameborder="0"></iframe>