body{margin:0;padding:0;background:orange}.parallax{position:relative;margin:1000px auto;width:100%;height:500px;background-attachment:fixed;background-position:50% 50%;background-repeat:no-repeat;background-size:cover}.parallax.bg1{background-image:url(../images/landscape1.jpg)}.parallax.bg2{background-image:url(../images/landscape2.jpg)}