.cloud img {
    width: 100%;
    height: 300px;
    left: 0;
    top: 0;
    z-index: 1;
    position: absolute;
    -webkit-user-select: none; 
    -moz-user-select: none;   
    -ms-user-select: none;
    user-select: none;    
    pointer-events: none;
}
@-webkit-keyframes animCloud {
    from {
        -webkit-transform: translateX(100%)
    }
    to {
        -webkit-transform: translateX(-100%)
    }
}
@-moz-keyframes animCloud {
    from {
        -moz-transform: translateX(100%)
    }
    to {
        -moz-transform: translateX(-100%)
    }
}
@keyframes animCloud {
    from {
        -webkit-transform: translateX(100%);
        -moz-transform: translateX(100%);
        -ms-transform: translateX(100%);
        -o-transform: translateX(100%);
        transform: translateX(100%)
    }
    to {
        -webkit-transform: translateX(-100%);
        -moz-transform: translateX(-100%);
        -ms-transform: translateX(-100%);
        -o-transform: translateX(-100%);
        transform: translateX(-100%)
    }
}
.cloud1 {
    -webkit-animation: animCloud 20s infinite linear;
    -moz-animation: animCloud 20s infinite linear;
    animation: animCloud 20s infinite linear
}
.cloud2 {
    -webkit-animation: animCloud 40s infinite linear;
    -moz-animation: animCloud 40s infinite linear;
    animation: animCloud 40s infinite linear
}
.cloud3 {
    -webkit-animation: animCloud 60s infinite linear;
    -moz-animation: animCloud 60s infinite linear;
    animation: animCloud 60s infinite linear
}
.cloud4 {
    -webkit-animation: animCloud 80s infinite linear;
    -moz-animation: animCloud 80s infinite linear;
    animation: animCloud 80s infinite linear
}