Scientific Calculator

Enhanced prompt:

Design and implement a professional-grade scientific calculator application using modern web technologies. Your calculator should replicate the functionality of high-end hardware calculators, providing a comprehensive set of arithmetic and advanced scientific operations.

Functional Requirements:

1. Core Arithmetic Engine:

   • Implement addition, subtraction, multiplication, and division (including floating point) with proper operator precedence and associativity, following the order of operations (PEMDAS/BODMAS).
   • Handle negative numbers, decimals, and fractions correctly.

2. Scientific Calculations:

   • Include a full range of trigonometric functions: sine, cosine, tangent, cotangent, arcsine, arccosine, arctangent, and arccotangent.
   • Implement logarithmic functions: natural log (ln), common log (log), and logarithmic base change.
   • Add exponential functions: power (x^y), square root (√x), cube root (x^(1/3)), and x^n.
   • Incorporate statistical functions: mean, median, mode, standard deviation, variance, and range (if applicable).
   • Provide a toggle between degree and radian modes for trigonometric calculations.

3. Memory Operations:

   • Implement the standard calculator memory functions: M+ (add to memory), M- (subtract from memory), MR (recall from memory), and MC (clear memory).
   • Visually indicate when memory is active (e.g., blinking memory display) and when it's empty.
   • Ensure memory can handle numbers of various sizes without overflowing.

4. Calculation History:

   • Maintain a scrollable log of all calculations performed, displaying the expression and result.
   • Allow users to clear the history log or save it for later reference.
   • Handle long expressions by truncating and providing a "see more" option.

5. User Interaction:

   • Provide full keyboard support with appropriate key mappings:
     • Numeric keys for digits and decimals.
     • Arithmetic operators for +, -, *, /, and other functions.
     • Function keys for memory, clear, and special operations.
     • Shortcuts for common actions (e.g., Enter for equal, Backspace for clear).
   • Implement copy and paste functionality for results and expressions.

6. Error Handling:

   • Handle division by zero, invalid operations (e.g., √-1), and numerical overflow conditions gracefully.
   • Display clear, context-specific error messages using standard error codes.
   • Provide user-friendly instructions on how to resolve errors.

7. Responsive Design:

   • Create a responsive layout that transforms between a standard layout (for basic arithmetic) and a scientific layout (for advanced functions) based on:
     • Screen width (e.g., 800px for scientific mode).
     • Screen orientation (landscape for scientific, portrait for standard).
   • Ensure all functionality is accessible in both modes.
   • Maintain a consistent visual style and layout across both modes.

8. Theming:

   • Develop multiple visual themes: classic (retro), modern (flat), and high contrast (accessibility).
   • Allow users to select their preferred theme.
   • Maintain a consistent theme across the entire interface.

9. Optional Sound Feedback:

   • Implement sound effects for button presses (e.g., click, beep).
   • Allow users to enable or disable sound effects.
   • Provide volume control with a mute function.

10. Performance Considerations:

• Optimize the JavaScript calculations for speed and efficiency.
• Minimize layout shifts and repaints.
• Ensure the application remains responsive with large expressions or calculations.

Constraints and Deliverables:

• The calculator should be implemented using HTML5 for structure, CSS3 for styling, and JavaScript (ES6+) for functionality.
• Ensure cross-browser compatibility (Chrome, Firefox, Safari, Edge).
• The application should be responsive and function on both desktop and mobile devices.
• The code should be clean, modular, and well-commented for easy maintenance and future enhancements.
• Provide clear documentation explaining the implementation choices, error codes, and API interfaces (if any).
• Include unit tests to verify the correctness of the arithmetic engine and error handling.
• The calculator should have a professional appearance, with a clean, intuitive interface.
• The design should be visually appealing and consistent with modern web standards.

Your task is to create a comprehensive design document detailing the architecture, data structures, and algorithms used in the calculator. You should also provide a working prototype or demo that meets all the specified requirements. The final deliverable should be the complete source code for the application, along with the documentation and tests.