fix: improve dark mode compatibility and chart visibility

- Fix TopQuestionsChart with proper dark mode colors using CSS variables and shadcn/ui components
- Enhance ResponseTimeDistribution with thicker bars (maxBarSize: 60)
- Replace GeographicMap with dark/light mode compatible CartoDB tiles
- Add custom text selection background color with primary theme color
- Update all loading states to use proper CSS variables instead of hardcoded colors
- Fix dashboard layout background to use bg-background instead of bg-gray-100

components/magicui/animated-shiny-text.tsx

@@ -0,0 +1,39 @@
+import { ComponentPropsWithoutRef, CSSProperties, FC } from "react";
+
+import { cn } from "@/lib/utils";
+
+export interface AnimatedShinyTextProps
+  extends ComponentPropsWithoutRef<"span"> {
+  shimmerWidth?: number;
+}
+
+export const AnimatedShinyText: FC<AnimatedShinyTextProps> = ({
+  children,
+  className,
+  shimmerWidth = 100,
+  ...props
+}) => {
+  return (
+    <span
+      style={
+        {
+          "--shiny-width": `${shimmerWidth}px`,
+        } as CSSProperties
+      }
+      className={cn(
+        "mx-auto max-w-md text-neutral-600/70 dark:text-neutral-400/70",
+
+        // Shine effect
+        "animate-shiny-text bg-clip-text bg-no-repeat [background-position:0_0] [background-size:var(--shiny-width)_100%] [transition:background-position_1s_cubic-bezier(.6,.6,0,1)_infinite]",
+
+        // Shine gradient
+        "bg-gradient-to-r from-transparent via-black/80 via-50% to-transparent  dark:via-white/80",
+
+        className,
+      )}
+      {...props}
+    >
+      {children}
+    </span>
+  );
+};