.rotation {
            -webkit-animation-name: rotation;
            -webkit-animation-duration: 30s;
            -moz-animation-name: rotation;
            -moz-animation-duration: 30s;
        }

#sun {
    background: url("http://img.mukewang.com/55ade004000106c202010201.png") no-repeat;
    position: absolute;
    z-index: 1;
    top: -30px;
    height: 201px;
    width: 201px;
    right: 40%;

}

  @-webkit-keyframes rotation {

        0% {
    transform: translateX(0) translateY(0);
        }
100% {
    transform: translateX(-2000px) translateY(400px);
}
            /*？*/
        }
        
        @-moz-keyframes rotation {
            /*？*/
            0% {
    transform: translateX(0) translateY(0);
}
100% {
    transform: translateX(-2000px) translateY(400px);
}
        }