@keyframes rainbowText {
    0% {
        color: red;
    }

    20% {
        color: orange;
    }

    40% {
        color: yellow;
    }

    60% {
        color: green;
    }

    80% {
        color: blue;
    }

    100% {
        color: red;
    }
}

.rainbow {
    font-weight: bold;
    animation: rainbowText 3s linear infinite;
}