body {
    background-color: black;
    color: white;
    font-family: Verdana, Geneva, Tahoma, sans-serif;
    margin: 8%;
}

a:hover {
    background: linear-gradient(to right, #6666ff, #0099ff, #00ff00, #ff3399, #6666ff);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    animation: rainbow_animation 1s ease-in-out infinite;
    background-size: 400% 100%;
    filter: drop-shadow(red 0px 0px 2px);
}

a:active {
    filter: drop-shadow(blue 0px 0px 2px);
}

@keyframes rainbow_animation {

    0%,
    100% {
        background-position: 0 0;
    }

    50% {
        background-position: 100% 0;
    }
}