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

.container {
    display: grid;
    grid-template-columns: repeat(var(--columns), 1fr);
}

.container span {
    font-size: 25px;
    width: 1em;
    height: 1em;
    color: lime;
    background-color: currentColor;
    transform: scale(0);
    animation: spin 5s linear infinite;
    animation-delay: calc(var(--delay) * 1s);
}

@keyframes spin {
    0% {
        transform: rotate(0deg) scale(1);
    }

    5%, 15% {
        transform: rotate(90deg) scale(0);
        background: white;
    }

    17.5% {
        transform: rotate(180deg) scale(1);
        background-color: currentColor;
    }

    20%, 100% {
        transform: rotate(90deg) scale(0);
    }
}