Update OpenAI API key and enhance app functionality: Replace the OpenAI API key in the .env file for improved access. Refactor app.py to include error handling for missing API keys and implement dark mode functionality with session management. Update README.md to reflect the use of Tailwind CSS via CDN and document the Content Security Policy (CSP) adjustments. Enhance mindmap data loading with a new API endpoint for refreshing data, ensuring better user experience during database connection issues. Update styles and templates for improved UI consistency and responsiveness.

static/css/tailwind.min.css

@@ -0,0 +1,16 @@
+/*
+ * Tailwind CSS v3.4.16
+ * 
+ * This is a placeholder file. For production, you should:
+ * 1. Install Tailwind CSS as a PostCSS plugin: https://tailwindcss.com/docs/installation
+ * 2. Run the Tailwind CLI to compile this file with your custom configuration
+ * 3. Replace this file with the compiled CSS
+ *
+ * The actual file should be generated using:
+ * npx tailwindcss -i ./src/input.css -o ./static/css/tailwind.min.css --minify
+ */
+ 
+/* Base Tailwind imports */
+@tailwind base;
+@tailwind components;
+@tailwind utilities;