feat: Add CalendarSelector component and install new dependencies.

client/src/index.css

@@ -0,0 +1,26 @@
+@tailwind base;
+@tailwind components;
+@tailwind utilities;
+
+@layer base {
+  body {
+    @apply bg-slate-50 text-slate-900 antialiased;
+  }
+}
+
+/* Custom animations if needed outside of Tailwind config */
+@keyframes fade-in {
+  from {
+    opacity: 0;
+    transform: translateY(10px);
+  }
+
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
+}
+
+.animate-fade-in {
+  animation: fade-in 0.6s ease-out forwards;
+}