style.css

@import url("https://fonts.googleapis.com/css?family=Poppins:100,200,300,400,500,600,700,800,900");
*
{
    font-family: 'Poppins', sans-serif;
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    /* background: #0e1538; */
    background: black;
}

.box {
    position: relative;
    width: 300px;
    height: 300px;
    display: flex;
    justify-content: center;
    align-items: center;
    background: black;
    overflow: hidden;
    border-radius: 16px;
    padding-left: 0px;
}

.box::before {
    content: '';
    position: absolute;
    width: 150px;
    height: 140%;
    background: linear-gradient(#00ccff, #d400d4);
    animation: animate 4s linear infinite;
}

.box::after
{
    content: '';
    position: absolute;
    inset : 4px;
    background: black;
    border-radius: 16px;
}

@keyframes animate {
    0%
    {
        transform: rotate(0deg);

    }
    100%
    {
        transform: rotate(360deg);
    }
}

.box h2 {
    color: #ffff;
    font-size: 2em;
    justify-content: center;
    text-align: center;
    padding-left: 0px;
    z-index: 10;
    animation: example 6s linear infinite;
}

.box h2::before {
    color: #00ccff;
    font-size: 2em;
    justify-content: center;
    text-align: center;
    padding-left: 0px;
    z-index: 10;
    animation: example 3s linear infinite;
}

.box h2::after {
    color: #d400d4;
    font-size: 2em;
    /* justify-content: center; */
    /* text-align: center; */
    /* padding-left: 0px; */
    z-index: 10;
}

@keyframes example {
    0%
    {
        transform:translateX(0px);
        transform:translateY(0px);
        color: #ffff;     
    }
    25%
    {
        transform:translateX(50px);
        transform:translateY(50px); 
        color: #fcc8fc; 
    }
    50%
    {
        transform:translateX(0px);
        transform:translateY(0px); 
        color: #fd83fd; 
    }
    75%
    {
        transform:translateX(-50px);
        transform:translateY(-50px);
        color: #5edaf9;  
    }
    100%
    {
        transform:translateX(0px);
        transform:translateY(0px);
        color: #ffff; 
    }
}