.green1,.green2,.green3,.green4{ position: fixed; z-index: 20; pointer-events: none;}
.green1,.green2{ width: 420px; height: 160px; background: url("green.gif") no-repeat; top: -10px;}
.green1{ left: -15px; transform: rotateY(180deg);}
.green2{ right: -15px;}
.green3{ width: 330px; height: 200px; background: url("green2.gif") no-repeat; bottom: 0; left: 0;}
.green4{ width: 320px; height: 300px; background: url("green.webp") no-repeat; bottom: 0; right: 0; -webkit-animation: green 2s steps(50) infinite;animation: green 2s steps(50) infinite;}


@-webkit-keyframes green{
    to{
        background-position: 0 -15000px;
    }
}