Replace zen grids with css grid. Move print styles print style file. Remove Drupal specific styles.

layouts/partials/menu.html

@@ -1,7 +1,6 @@
 {{ $currentSection := .Section }}
 {{ $currentID := .UniqueID }}
-<div class="layout-swap__top layout-3col__full">
-<nav class="main-menu" role="navigation">
+<nav class="main-menu layout__navigation layout__full" role="navigation">
 <h2 class="visually-hidden">Main menu</h2>
 <ul class="navbar clearfix">
 <li><a class="{{ if .IsHome }}active{{ end }}" href="/">{{ i18n "menu_home" }}</a></li>
@@ -13,4 +12,3 @@
 {{ end -}}
 </ul>
 </nav>
-</div>

layouts/partials/meta_cache.html

@@ -1 +1,2 @@
 <link rel="stylesheet" href="/css/styles.css{{ if $.Param "cacheBustCSS" }}?{{ readFile "/public/css/styles.css" | sha1 }}{{ end }}">
+<link rel="stylesheet" href="/css/print.css" media="print">

layouts/partials/sidebar.html

@@ -1,5 +1,5 @@
 {{ $currentID := .UniqueID }}
-<aside class="layout-3col__right-sidebar" role="complementary">
+<aside class="sidebar layout__second-sidebar" role="complementary">
 {{ range $.Site.Home.Sections -}}
 <section>
 <h4 class="menu"><a class="{{ if eq $currentID .UniqueID }}active{{ end }}" href="{{ .RelPermalink }}">{{ .Title }}</a></h4>