Make cover full bleed, TOC single column readable, and unify header with clean kebab menu on desktop

app/static/cookbook.css

@@ -1487,13 +1487,11 @@
 
 /* --- Mobile Navigation: 3-Punkte (Kebab) Menü --- */
 .desktop-nav-actions {
-  display: flex;
-  align-items: center;
-  gap: 10px;
+  display: none !important;
 }
 
 .mobile-nav-wrapper {
-  display: none;
+  display: block !important;
   position: relative;
 }
 
@@ -1726,8 +1724,9 @@
 }
 
 .toc-columns {
-  columns: 2;
-  column-gap: 10mm;
+  columns: 1;
+  column-count: 1;
+  column-gap: 0;
   flex: 1;
 }
 
@@ -1797,7 +1796,7 @@
 }
 
 .toc-rec-title {
-  max-width: 75%;
+  max-width: 84%;
   overflow: hidden;
   text-overflow: ellipsis;
   white-space: nowrap;