:root{--header-height:64px;--footer-height:64px}body,html{height:100%;margin:0;padding:0}body{background-image:url(/bg_image_4.jpg);background-size:cover;background-repeat:no-repeat;background-attachment:fixed;background-position:50%;overflow:hidden}main{height:100vh;overflow-y:auto;padding-top:var(--header-height);padding-bottom:var(--footer-height);box-sizing:border-box}