body>.main {
   
    position: absolute;
    left: 0px;
    top: 0px;
    right: 0px;
    bottom: 0px;
}

body>.main>.page {
   
    position: absolute;
    left: 0px;
    top: 0px;
    right: 0px;
    bottom: 0px;
}

body>.main>.page.hidden,
body>.main>.page .hidden {
    display: none;
}