diff --git a/frontend/textbooks.html b/frontend/textbooks.html
index 6478197..cbba5d0 100644
--- a/frontend/textbooks.html
+++ b/frontend/textbooks.html
@@ -55,6 +55,10 @@
     .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.sky    { background:linear-gradient(135deg, #0c4a6e 0%, #0284c7 60%, #7dd3fc 100%); }
+    .tb-cover.red    { background:linear-gradient(135deg, #7f1d1d 0%, #dc2626 60%, #f87171 100%); }
+    .tb-cover.orange { background:linear-gradient(135deg, #9a3412 0%, #ea580c 60%, #fb923c 100%); }
+    .tb-cover.yellow { background:linear-gradient(135deg, #854d0e 0%, #ca8a04 60%, #fde047 100%); }
 
     .tb-cover::before {
       content: attr(data-watermark);
@@ -115,6 +119,10 @@
     .tb-progress.teal   .tb-progress-fill { background:#0d9488; }
     .tb-progress.cyan   .tb-progress-fill { background:#0891b2; }
     .tb-progress.emerald .tb-progress-fill { background:#059669; }
+    .tb-progress.sky    .tb-progress-fill { background:#0284c7; }
+    .tb-progress.red    .tb-progress-fill { background:#dc2626; }
+    .tb-progress.orange .tb-progress-fill { background:#ea580c; }
+    .tb-progress.yellow .tb-progress-fill { background:#ca8a04; }
     .tb-progress-text {
       display:flex; justify-content:space-between; align-items:center;
       font-size:.74rem; color:var(--text-3);
@@ -145,6 +153,10 @@
     .tb-btn.primary.teal   { background:#0d9488; }
     .tb-btn.primary.cyan   { background:#0891b2; }
     .tb-btn.primary.emerald { background:#059669; }
+    .tb-btn.primary.sky    { background:#0284c7; }
+    .tb-btn.primary.red    { background:#dc2626; }
+    .tb-btn.primary.orange { background:#ea580c; }
+    .tb-btn.primary.yellow { background:#ca8a04; }
     .tb-btn.primary:hover { filter:brightness(1.1); }
     .tb-btn svg { width:14px; height:14px; }