diff --git a/frontend/textbooks.html b/frontend/textbooks.html
index 49c2976..6232549 100644
--- a/frontend/textbooks.html
+++ b/frontend/textbooks.html
@@ -51,6 +51,10 @@
     .tb-cover.pink   { background:linear-gradient(135deg, #be185d 0%, #db2777 60%, #ec4899 100%); }
     .tb-cover.indigo { background:linear-gradient(135deg, #3730a3 0%, #4f46e5 60%, #818cf8 100%); }
     .tb-cover.rose   { background:linear-gradient(135deg, #9f1239 0%, #e11d48 60%, #fb7185 100%); }
+    .tb-cover.teal   { background:linear-gradient(135deg, #134e4a 0%, #0d9488 60%, #14b8a6 100%); }
+    .tb-cover.cyan   { background:linear-gradient(135deg, #164e63 0%, #0891b2 60%, #22d3ee 100%); }
+    .tb-cover.emerald{ background:linear-gradient(135deg, #064e3b 0%, #059669 60%, #34d399 100%); }
+    .tb-cover.amber-light{ background:linear-gradient(135deg, #92400e 0%, #d97706 60%, #fbbf24 100%); }
 
     .tb-cover::before {
       content: attr(data-watermark);