CSS3动画设置后台登录页背景切换图片

CSS3的动画很实用很好用，简单几句话就可以做出一个好看而且过渡平滑的body背景图片，不多说，来来来，上代码

 body{
     animation:mybg 7s;
     -webkit-animation:mybg 7s; /* Safari and Chrome */
     -moz-animation:mybg 7s; /* Safari and Chrome */
     animation-iteration-count:infinite;
 }
 @keyframes mybg{
     0% {background:url(/static/admin/images/banner_1.jpg);background-size:100%;}
     50% {background:url(/static/admin/images/banner_2.jpg);background-size:100%;}
     100% {background:url(/static/admin/images/banner_1.jpg);background-size:100%;}
 }
 /* Safari and Chrome */
 @keyframes mybg{
     0% {background:url(/static/admin/images/banner_1.jpg);background-size:100%;}
     50% {background:url(/static/admin/images/banner_2.jpg);background-size:100%;}
     100% {background:url(/static/admin/images/banner_1.jpg);background-size:100%;}
 }
 /* Firfox */
 @keyframes mybg{
     0% {background:url(/static/admin/images/banner_1.jpg);background-size:100%;}
     50% {background:url(/static/admin/images/banner_2.jpg);background-size:100%;}
     100% {background:url(/static/admin/images/banner_1.jpg);background-size:100%;}
 }