Create src/app.py

src/app.py

@@ -0,0 +1,98 @@
+import pandas as pd
+import streamlit as st
+from openai import OpenAI
+import os
+
+st.set_page_config(
+    page_title="Civil Engineering Numerical Solver",
+    page_icon="📐",
+    layout="centered"
+)
+
+PRIMARY_COLOR = "#0F2C59"
+
+st.markdown(
+    f"""
+    <h1 style='text-align:center; color:{PRIMARY_COLOR};'>
+        Procelevate – Civil Engineering Numerical Solver
+    </h1>
+    <p style='text-align:center; font-size:18px;'>
+        Solve Civil Engineering numericals with step-by-step explanations.
+    </p>
+    """,
+    unsafe_allow_html=True,
+)
+
+# Load API key from HF Secrets
+api_key = os.getenv("OPENAI_API_KEY")
+
+if not api_key:
+    st.warning("⚠️ Add OPENAI_API_KEY in Space → Settings → Secrets")
+else:
+    client = OpenAI(api_key=api_key)
+
+st.sidebar.header("Instructions")
+st.sidebar.write("""
+1. Choose subject  
+2. Enter any Civil Engineering numerical  
+3. Click **Solve Numerical**  
+4. Get formulas, steps & final answer  
+""")
+
+subjects = [
+    "Structural Engineering",
+    "RCC / Concrete Design",
+    "Steel Design",
+    "Soil Mechanics / Geotech",
+    "Fluid Mechanics",
+    "Transportation Engineering",
+    "Surveying",
+    "Environmental Engineering",
+]
+
+subject_choice = st.selectbox("Select Subject", subjects)
+
+problem = st.text_area(
+    "Enter the Numerical",
+    height=180,
+    placeholder="Example: A 4m beam carries 15 kN/m UDL. Find max bending moment."
+)
+
+if st.button("Solve Numerical", use_container_width=True):
+    if not api_key:
+        st.error("Missing API key. Add OPENAI_API_KEY in Space settings.")
+    elif not problem.strip():
+        st.error("Please enter a numerical problem.")
+    else:
+        with st.spinner("Solving… please wait ⏳"):
+
+            prompt = f"""
+            You are an expert Civil Engineering tutor. Solve the numerical step-by-step.
+
+            Subject: {subject_choice}
+
+            Numerical:
+            {problem}
+
+            Provide:
+            1. Formula (with symbol meanings)
+            2. Substitution with units
+            3. Step-by-step solution
+            4. Final answer with correct units
+            5. ASCII diagram (if useful)
+            6. Concept explanation
+            7. Common mistakes students make
+            """
+
+            try:
+                response = client.chat.completions.create(
+                    model="gpt-4.1",
+                    messages=[{"role": "user", "content": prompt}]
+                )
+                result = response.choices[0].message["content"]
+
+                st.success("Solved!")
+                st.markdown("### 🧮 Step-by-Step Solution")
+                st.write(result)
+
+            except Exception as e: