page {
overflow:hidden;
position:fixed;
/* background-image:url('http://p0d5ombx1.bkt.clouddn.com/login.png'); */
background: url(data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAAD/2wBDAAkGBwgHBgkICAgKCgkLDhcPDg0NDhwUFREXIh4jIyEeICAlKjUtJScyKCAg0P/aAAgBAwEBPwAWA//Z) no-repeat;
margin: 0px;
/*下面的是关键的设置100%显示*/
background-size: auto 100%;
}