.cloud-01 {
    top: 5%;
    position: absolute;
    animation: run01 linear 20s infinite;
    -webkit-animation: run01 linear 20s infinite;
    -moz-animation: run01 linear 20s infinite;
    -o-animation: run01 linear 20s infinite;
    -ms-animation: run01 linear 20s infinite;
    z-index: 1;
}

@keyframes run01 {
    0% {
        margin-left: 100%;
    }
    100% {
        margin-left: -25%;
    }
}

@-moz-keyframes run01 {
    0% {
        margin-left: 100%;
    }
    100% {
        margin-left: -25%;
    }
}

@-webkit-keyframes run01 {
    0% {
        margin-left: 100%;
    }
    100% {
        margin-left: -25%;
    }
}

@-o-keyframes run01 {
    0% {
        margin-left: 100%;
    }
    100% {
        margin-left: -25%;
    }
}

@-ms-keyframes run01 {
    0% {
        margin-left: 100%;
    }
    100% {
        margin-left: -25%;
    }
}