Optimize Tkinter App Speed and UI

My desktop application is written entirely in Python with Tkinter. It works, but its start-up feels sluggish and the interface still wears the default look. I’d like you to dive into the code, shave seconds off the launch time, and give the widgets a modern polish—while staying inside the Tkinter ecosystem.

Performance focus
Faster load time is the top priority. If heavy imports, blocking I/O, or eager widget creation are the culprits, please profile, refactor, and streamline. Feel free to use tools such as cProfile, line_profiler, or even a custom timing script, and apply techniques like lazy loading, efficient event handling, or threading without altering behaviour.

User-interface refresh
Once the app is leaner, spruce up the UI. Clean, consistent ttk styling, improved geometry management, and clearer fonts or colours are all welcome. I’m open to themed-Tk/ttk or light custom widgets as long as dependencies stay minimal.

Deliverables
• Updated Python source files, commented to highlight each change
• A brief before-and-after profiling report and screenshots of the new UI
• Simple run instructions for Windows and Linux

There’s no strict deadline, so you can take the time needed to craft a maintainable solution. Let’s make this app start quickly and look as good as it performs.