doctype html html(lang="de") head title= "Project List" meta(charset="UTF-8") meta(name="viewport", content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no") link(rel="stylesheet", type="text/css", href="https://transfer.hft-stuttgart.de/css/bootstrap/bootstrap.css") link(rel="stylesheet", href="https://use.fontawesome.com/releases/v5.8.2/css/all.css", integrity="sha384-oS3vJWv+0UjzBfQzYUhtDYW+Pj2yciDJxpsK1OYPAYjqT085Qq/1cq5FLXAZQ7Ay", crossorigin="anonymous") style. .collapse { display: none; } .collapse.in { display: block; } .collapsing { position: relative; height: 0; overflow: hidden; -webkit-transition-timing-function: ease; -o-transition-timing-function: ease; transition-timing-function: ease; -webkit-transition-duration: .35s; -o-transition-duration: .35s; transition-duration: .35s; -webkit-transition-property: height,visibility; -o-transition-property: height,visibility; transition-property: height,visibility; } .warning { color: red; font-size: 11px; } body include landingpage.html // jQuery script(src="https://code.jquery.com/jquery-3.3.1.min.js") script(src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js", integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1", crossorigin="anonymous") // Bootstrap script(src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous") // Header if isUserAuthenticated script(src="/js/headfootLogout.js") else script(src="/js/headfoot.js")