UI/UX enhancements: refined footer layout, dashboard sidebar fixes, header tweaks, and theme alignment

src/app/globals.css

@@ -70,6 +70,17 @@ body {
   @apply antialiased selection:bg-primary/20;
 }
 
+/* ─── Light mode: flatten card shadows so they don't look 3D/lifted ─── */
+:root:not(.dark) .shadow-sm,
+:root:not(.dark) .shadow,
+:root:not(.dark) .shadow-md,
+:root:not(.dark) .shadow-lg,
+:root:not(.dark) .shadow-xl,
+:root:not(.dark) .shadow-2xl,
+:root:not(.dark) [class*="shadow-"] {
+  box-shadow: none !important;
+}
+
 @layer utilities {
   .text-balance {
     text-wrap: balance;