Redesign UI with zen cards, split AI panel, and PWA install support.

Learn uses 64-gua card grid; liuyao/bazi/combined use two input cards plus sticky right AI panel; add manifest, service worker, and install prompt.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/globals.css

@@ -72,7 +72,7 @@
   }
 
   body {
-    @apply gap flex flex-col bg-background text-foreground;
+    @apply gap flex flex-col bg-background text-foreground zen-bg;
   }
 
   body {
@@ -106,4 +106,20 @@
   ::-webkit-scrollbar-thumb {
     @apply rounded-md bg-border;
   }
+
+  .zen-bg {
+    background-image:
+      radial-gradient(ellipse 80% 50% at 50% -20%, hsl(40 20% 90% / 0.5), transparent),
+      radial-gradient(circle at 100% 100%, hsl(30 15% 92% / 0.4), transparent 40%);
+  }
+
+  .dark .zen-bg {
+    background-image:
+      radial-gradient(ellipse 80% 50% at 50% -20%, hsl(30 10% 20% / 0.5), transparent),
+      radial-gradient(circle at 100% 100%, hsl(25 8% 15% / 0.4), transparent 40%);
+  }
+
+  .zen-card-glow {
+    background: radial-gradient(circle, hsl(var(--primary) / 0.06) 0%, transparent 70%);
+  }
 }