Create new Flutter app

The prompt requests the creation of a new app with a neumorphic design, similar to a household account book, using Flutter.

src/components/AddTransactionButton.tsx

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+
+import React, { useState } from 'react';
+import { PlusIcon, MinusIcon, X } from 'lucide-react';
+import { cn } from '@/lib/utils';
+
+const AddTransactionButton = () => {
+  const [isOpen, setIsOpen] = useState(false);
+  
+  return (
+    <div className="fixed bottom-24 right-6 z-20">
+      {isOpen && (
+        <div className="absolute bottom-16 right-0 flex flex-col gap-3 items-end animate-slide-up">
+          <button 
+            className="neuro-flat p-4 text-neuro-expense flex items-center gap-2"
+            onClick={() => setIsOpen(false)}
+          >
+            <span className="text-sm font-medium">지출</span>
+            <MinusIcon size={18} />
+          </button>
+          <button 
+            className="neuro-flat p-4 text-neuro-income flex items-center gap-2"
+            onClick={() => setIsOpen(false)}
+          >
+            <span className="text-sm font-medium">수입</span>
+            <PlusIcon size={18} />
+          </button>
+        </div>
+      )}
+      
+      <button 
+        className={cn(
+          "p-4 rounded-full transition-all duration-300 text-white",
+          isOpen 
+            ? "bg-red-500 rotate-45 shadow-lg" 
+            : "bg-neuro-accent shadow-neuro-flat hover:shadow-neuro-convex animate-pulse-subtle"
+        )}
+        onClick={() => setIsOpen(!isOpen)}
+      >
+        {isOpen ? <X size={24} /> : <PlusIcon size={24} />}
+      </button>
+    </div>
+  );
+};
+
+export default AddTransactionButton;