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

sass/navigation/breadcrumb/_breadcrumb.scss

@@ -11,10 +11,6 @@
 
 .breadcrumb,
 %breadcrumb {
-  @media print {
-    display: none;
-  }
-
   &__title {
     @extend %visually-hidden;
   }

sass/navigation/more-link/_more-link.scss

@@ -1,6 +1,6 @@
 // "More" link
 //
-// Styles the "Read more…" and "Help" links common in Drupal.
+// Styles the "Read more…" and "Help" links common on the web.
 //
 // Markup: more-link.twig
 //
@@ -26,15 +26,3 @@
     }
   }
 }
-
-//
-// Drupal selectors.
-//
-
-.more-help-link {
-  @extend %more-link;
-
-  a {
-    @extend %more-link__help-icon;
-  }
-}

sass/navigation/nav-menu/_nav-menu.scss

@@ -38,24 +38,3 @@
     }
   }
 }
-
-//
-// Drupal selectors.
-//
-
-.menu__item {
-  @extend %nav-menu__item;
-
-  &.is-expanded {
-    @extend %nav-menu__item--is-expanded;
-  }
-
-  &.is-collapsed {
-    @extend %nav-menu__item--is-collapsed;
-  }
-}
-
-// The active item in a Drupal menu.
-.menu a.active {
-  @extend %nav-menu__link--is-active;
-}

sass/navigation/navbar/_navbar.scss

@@ -32,21 +32,3 @@
     }
   }
 }
-
-//
-// Drupal selectors.
-//
-
-.main-navigation {
-  // Hide the block titles put into the main-navigation area of the page.tpl.php.
-  .block-menu .block__title,
-  .block-menu-block .block__title {
-    @extend %visually-hidden;
-  }
-
-  // Main menu and secondary menu links and menu block links.
-  .links,
-  .menu {
-    @extend %navbar;
-  }
-}

sass/navigation/pager/_pager.scss

@@ -13,10 +13,6 @@
   padding: 0;
   text-align: center;
 
-  @media print {
-    display: none;
-  }
-
   // A page item in the pager list.
   &__item {
     display: inline;
@@ -33,7 +29,7 @@
 }
 
 //
-// Drupal selectors.
+// Zen selectors.
 //
 
 // .pager-item     - A list item containing a page number in the list of pages.

sass/navigation/skip-link/_skip-link.scss

@@ -23,9 +23,5 @@
 
   &__wrapper {
     margin: 0;
-
-    @media print {
-      display: none;
-    }
   }
 }