feat: Implement website structure

- Add navigation with Themes, Puzzles, and Miscellany.
- Create "coming soon" pages for Puzzles and Miscellany.
- Create a Themes page with cards for various topics.
- Implement basic boxy layout.
- Prepare for future interactive additions and filtering.
- Set up for Netlify deployment.

src/components/ComingSoon.tsx

@@ -0,0 +1,55 @@
+import { Link } from "react-router-dom";
+import { ArrowLeft, Wrench } from "lucide-react";
+import { Button } from "@/components/ui/button";
+
+interface ComingSoonProps {
+  title: string;
+  description?: string;
+}
+
+const ComingSoon = ({ title, description }: ComingSoonProps) => {
+  return (
+    <div className="min-h-screen bg-background flex items-center justify-center px-4">
+      <div className="text-center max-w-2xl mx-auto">
+        <div className="w-24 h-24 bg-surface-variant rounded-full flex items-center justify-center mx-auto mb-8">
+          <Wrench className="w-12 h-12 text-muted-foreground" />
+        </div>
+        
+        <h1 className="text-4xl font-bold text-foreground mb-4">
+          {title}
+        </h1>
+        
+        <h2 className="text-2xl font-semibold text-accent mb-6">
+          Coming Soon
+        </h2>
+        
+        <p className="text-muted-foreground text-lg leading-relaxed mb-8">
+          {description || 
+            "We're working hard to bring you amazing interactive educational content. This section will be filled with engaging puzzles, tools, and resources to enhance your learning experience."
+          }
+        </p>
+        
+        <div className="bg-surface border border-outline rounded-lg p-6 mb-8">
+          <p className="text-sm text-muted-foreground">
+            Want to be notified when this section launches? We're building something special that will include:
+          </p>
+          <ul className="text-sm text-muted-foreground mt-3 space-y-1">
+            <li>• Interactive learning modules</li>
+            <li>• Real-time collaboration tools</li>
+            <li>• Progress tracking and analytics</li>
+            <li>• Customizable difficulty levels</li>
+          </ul>
+        </div>
+        
+        <Button asChild variant="outline">
+          <Link to="/" className="inline-flex items-center">
+            <ArrowLeft className="w-4 h-4 mr-2" />
+            Back to Home
+          </Link>
+        </Button>
+      </div>
+    </div>
+  );
+};
+
+export default ComingSoon;