Update requirements.txt

requirements.txt

@@ -1,4 +1,3 @@
-streamlit
-pandas
-openpyxl
-PyPDF2
+streamlit==1.26.0     # Main library for the web interface
+pandas==2.1.1         # For handling tabular data (fiber composition, results)
+plotly==5.15.0        # For 3D visualizations of water, energy, and carbon footprints