.clouds
{
    position: relative;
    top : 0;
    left: 0;
    width : 100%;
    height: 100%;
    overflow: hidden;
}


.clouds img
{
    position: fixed;
    bottom: 0;
    max-width: 100%;
    animation: cloudAnimation calc(8s * var(--i)) linear infinite;
}

@keyframes cloudAnimation
{
    0%
    {
        transform: translateX(-100%);
    }
    100%
    {
        transform: translateX(100%);
    }
}