styles.css

:root {
    font-size: 15px;
    --lighting-size: 300px;
    --lighting-color: #9333ea;
    --lighting-highlight-color: #d8b4fe;
}

body {
    --x: 0px;
    --y: 0px;

    max-width: 600px;
    margin: 80px auto;

    font-size: 1.5rem;
    font-family: Helvetica;
    background-color: #020617;
    color: #94a3b8;
}

div {
    padding: 40px;
}

a {
    text-decoration: none;
    color: #9333ea;
    display: inline-block;

    background-image: radial-gradient(var(--lighting-highlight-color), var(--lighting-color), var(--lighting-color));
    background-size: var(--lighting-size) var(--lighting-size);
    background-repeat: no-repeat;

    background-position-x: calc(var(--x) - var(--positionX) - calc(var(--lighting-size) / 2));
    background-position-y: calc(var(--y) - var(--positionY) - calc(var(--lighting-size) / 2));

    background-color: var(--lighting-color);

    color: transparent;
    -webkit-background-clip: text;
    background-clip: text;
}

.card {
    width: 400px;
    height: 400px;
    position: relative;
    border-radius: 40px;
    padding: 40px;
    box-sizing: border-box;
    overflow: hidden;
    box-shadow: inset 0px 0px 40px rgba(0, 0, 0, .8), 0px 8px 20px rgba(0, 0, 0, .6);
}

.card::after {
    content: '';
    position: absolute;
    top: -300px;
    right: -300px;
    bottom: -300px;
    left: -300px;
    background: conic-gradient(from 180deg at 50% 50%, #12001B -97.5deg, #000000 14.05deg, #040EFF 54.01deg, #8000FF 113.42deg, #00B6B6 185.62deg, #12001B 262.5deg, #000000 374.05deg);
    filter: blur(60px) brightness(1.5);
    z-index: -1;
    animation: 30s move linear infinite;
}

.card>h2 {
    margin: 0;
    padding: 0;
    font-size: 60px;
    letter-spacing: -1px;
    color: #fff;
    text-shadow: 0px 2px 4px rgba(0, 0, 0, .3);
}

span {
    font-size: 50px;
    font-weight: normal;
    display: block;
}

.card>div {
    background-color: rgba(0, 0, 0, 0.5);
    padding: 20px 40px;
    font-size: 32px;
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    color: #fff;
}

@keyframes move {
    from {
        transform: rotate(180deg);
    }

    to {
        transform: rotate(540deg);
    }
}