body {
    margin: 0;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: black;
    overflow: hidden;
}

.container {
    width: 30em;
    font-size: 12px;
    color: lime; 
    display: flex;
    align-items: center;
    justify-content: center;
    animation: change-color 5s linear infinite;
}

@keyframes change-color {
    to {
        filter: hue-rotate(1turn);
    }
}

.container span {
    position: absolute;
    --diameter: calc(5em + (var(--n) - 1) * 3em);
    width: var(--diameter);
    height: var(--diameter);
    border-style: solid;
    border-width: 1em 1em 0 0;
    border-color: currentColor transparent;
    border-radius: 50%;
    animation: rotating linear infinite;
    animation-duration: calc(5s / (9 - var(--n) + 1));
}

@keyframes rotating {
    to {
        transform: rotate(1turn);
    }
}

.container span:nth-child(1) {
    --n: 1;
}

.container span:nth-child(2) {
    --n: 2;
}

.container span:nth-child(3) {
    --n: 3;
}

.container span:nth-child(4) {
    --n: 4;
}

.container span:nth-child(5) {
    --n: 5;
}

.container span:nth-child(6) {
    --n: 6;
}

.container span:nth-child(7) {
    --n: 7;
}

.container span:nth-child(8) {
    --n: 8;
}

.container span:nth-child(9) {
    --n: 9;
}