Re-add styles for 404 page

404.php

@@ -15,7 +15,7 @@ get_header();
         <header>
             <h1>Fehler: 404</h1>
         </header>
-        <div class="content error404">
+        <div class="content jumbo">
             <div class="icon">?!</div>
             <div class="message">Die angefragte Seite existiert leider nicht.</div>
         </div>

style.css

@@ -543,6 +543,21 @@ main.list footer time {
     content: "";
 }
 
+/* ==== Utilities: Jumbo content (used on 404 page) ==== */
+.content.jumbo {
+    text-align: center;
+}
+
+.content.jumbo .icon {
+    margin: 0.25em;
+    font-size: 10em;
+}
+
+.content.jumbo div {
+    display: inline-block;
+    vertical-align: middle;
+}
+
 /* ==== Text markup elements ==== */
 a {
     color: var(--accent-color);