body,html{height:100%}body{background-color:#f5f5f5;background:url(/bg.jpg) no-repeat fixed;background-size:cover;background-position:center}.box{width:100%;vertical-align:center;margin:auto;background:rgb(255,255,255,.8)}#particles-js{position:absolute;width:100%;height:100%;background-color:rgba(0,0,0,.7)}