#banner{position:relative;display:block;text-align:center;overflow:hidden;z-index:1}#banner::before{content:'';display:inline-block;vertical-align:middle;width:0;min-height:40vh}.parallax>.bg{position:absolute;top:initial;bottom:0;left:0;width:100%;height:100%;z-index:-1;background-position:center center;background-repeat:no-repeat;background-size:cover}