Basic dark theme handling

app/Resources/static/themes/material/css/dark_theme.scss

@@ -0,0 +1,73 @@
+.dark-theme {
+  body,
+  main #content,
+  #article,
+  .card,
+  .card-panel,
+  .card .card-reveal,
+  .card-stacked .preview:not(.preview--default),
+  .card .preview:not(.preview--default),
+  .collapsible-header,
+  .collection .collection-item,
+  .dropdown-content,
+  .nav-panel-add,
+  .nav-panel-search,
+  .side-nav,
+  .side-nav .collapsible-body,
+  .side-nav.fixed .collapsible-body,
+  .tabs {
+    background-color: black;
+  }
+
+  .dropdown-content li:hover,
+  .dropdown-content li.active,
+  .dropdown-content li.selected {
+    background-color: #575757;
+  }
+
+  main #content,
+  #article article,
+  #article article h1,
+  #article article h2,
+  #article article h3,
+  #article article h4,
+  #article article h5,
+  #article article h6,
+  .results a,
+  .side-nav li > a,
+  .side-nav li > a > i.material-icons {
+    color: #dfdfdf;
+  }
+
+  .grey-text.text-darken-4 {
+    color: #dfdfdf !important;
+  }
+
+  .side-nav li.active,
+  .side-nav li:not(.logo) > a:hover,
+  .side-nav .collapsible-header:hover,
+  .side-nav.fixed .collapsible-header:hover {
+    background-color: #333;
+  }
+
+  #article {
+    box-shadow: 0 0 10px #575757;
+  }
+
+  nav,
+  .card,
+  .side-nav {
+    box-shadow: 0 2px 2px 0 rgba(255, 255, 255, 0.4), 0 1px 5px 0 rgba(255, 255, 255, 0.4), 0 3px 1px -2px rgba(255, 255, 255, 0.4);
+  }
+
+  .logo img,
+  .preview.preview--default,
+  .typo-logo {
+    filter: invert(100%);
+  }
+
+  .border-bottom,
+  .collapsible {
+    border-color: #222;
+  }
+}

app/Resources/static/themes/material/css/index.scss

@@ -9,6 +9,7 @@
 @import 'nav';
 @import 'sidenav';
 @import 'various';
+@import 'dark_theme';
 
 /* Tools */
 @import 'fonts';

app/Resources/static/themes/material/css/media_queries.scss

@@ -15,7 +15,7 @@
 }
 
 @media screen and (min-width: 993px) {
-  body.entry main #content {
+  main #content {
     padding-left: 70px;
   }
 }

app/Resources/static/themes/material/css/nav.scss

@@ -71,7 +71,6 @@ nav {
   }
 
   .input-field input:focus {
-    background-color: #fff;
     border: 0;
     box-shadow: none;
     color: #444;
@@ -108,6 +107,11 @@ nav {
   }
 }
 
+.nav-panel-add,
+.nav-panel-search {
+  background-color: white;
+}
+
 .nav-form-button {
   padding: 0;
   background-color: transparent;