Feat: Add fully functional JavaScript logic and dynamic summary for BMI Calculator

[myweb768]

🚀 Overview
Hi there! I have successfully completed the core functionality and logic for the BMI Calculator project. The application now properly calculates the Body Mass Index (BMI) based on user inputs and dynamically displays the appropriate health status and detailed recommendations.
🛠️ Changes Made

1. Core Logic Implementation: Calculated BMI using the formula: $BMI = \frac{weight}{(height \times height)}$ and limited the result to 2 decimal places using .toFixed(2).
2. Dynamic Content Display: Handled conditional rendering (if/else if) based on standard BMI ranges ($<18.5$, $18.5-24.9$, $25-29.9$, and $\ge 30$).
3. DOM Manipulation: Toggled Tailwind CSS utility classes (hidden / block) to reveal the corresponding health status (.your_BMI) and health advice summaries (.BMI_Summery).
4. UI Reset and Flow Control: Implemented a resetting mechanism to clear previous results upon recalculation and hidden the input section to focus entirely on the output data.
5. Bug Fixes: Resolved edge-case issues regarding standard boundary numbers (e.g., handling exact values like $30.0$).

📷 Output Verification
The code has been thoroughly tested locally in the browser, and all DOM selectors mapping correctly with the index.html file.Please review my changes and let me know if any further adjustments are required.
Thank you!

[github-actions]

👋 @myweb768
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