style.css

*{
    margin:0 ;
    padding:0;
    box-sizing: border-box;
    font-family: 'Bad script',cursive;
}
body{
    display: flex;
    justify-content: center;
    align-items: center;
    min-height :100vh;
    background-color: rgb(17, 17, 17);
}
h2{
    display: flex;
    color:transparent;
    font-size: 8vw;
}
h2 span{
    animation: animate 3s linear infinite;
    animation-delay: calc(0.1s * var(--i));
}
@keyframes animate
{

    0%
    {

       color:#fff;
       filter: blur(0.5px)hue-rotate(0deg);
       text-shadow: 0 0 10px #00b3ff,
       0 0 20px #00b3ff,
       0 0 40px #00b3ff,
       0 0 80px #00b3ff,
       0 0 120px #00b3ff,
       0 0 200px #00b3ff,
       0 0 300px #00b3ff,
       0 0 400px #00b3ff
       ;

    }
    30%, 70%
    {
        color:#fff;
        filter:blur(0.5px) hue-rotate(360deg);
        text-shadow : 0 0 10px #00b3ff,
        0 0 20px #00b3ff,
        0 0 40px #00b3ff,
        0 0 80px #00b3ff,
        0 0 120px #00b3ff,
        0 0 400px #00b3ff
        ;
    }
    100%
    {
        color:transparent;
        box-shadow:none;
        filter:blur(0.5px) hue-rotate(0deg);

    }
}