app.py

import streamlit as st
import numpy as np
import sympy as sp
from sympy import symbols, Eq, solve

st.set_page_config(page_title="🧮 Scientific Calculator", layout="centered")

st.markdown("""
    <style>
        .main {
            background-color: #f0f2f6;
        }
        h1 {
            color: #4a90e2;
            text-align: center;
        }
        .stButton>button {
            background-color: #4a90e2;
            color: white;
        }
    </style>
""", unsafe_allow_html=True)

st.title("🧮 Scientific Calculator")

option = st.selectbox("Choose a calculator mode:", ["Basic Calculator", "Matrix Solver", "Equation Solver"])

if option == "Basic Calculator":
    st.header("Basic Calculator")
    expr = st.text_input("Enter expression (e.g., 2*(3+4)/5^2):")
    if st.button("Calculate"):
        try:
            expr = expr.replace("^", "**")
            result = eval(expr)
            st.success(f"Result: {result}")
        except Exception as e:
            st.error(f"Error: {e}")

elif option == "Matrix Solver":
    st.header("Matrix Solver")
    rows = st.number_input("Number of rows", min_value=1, max_value=5, value=2)
    cols = st.number_input("Number of columns", min_value=1, max_value=5, value=2)
    matrix = []
    st.write("Enter matrix values row-wise:")
    for i in range(int(rows)):
        row = st.text_input(f"Row {i+1} (comma-separated)")
        if row:
            matrix.append([float(x) for x in row.split(",")])
    if st.button("Calculate Determinant"):
        try:
            mat = np.array(matrix)
            if mat.shape[0] == mat.shape[1]:
                det = np.linalg.det(mat)
                st.success(f"Determinant: {det:.2f}")
            else:
                st.warning("Matrix must be square for determinant calculation.")
        except Exception as e:
            st.error(f"Error: {e}")

elif option == "Equation Solver":
    st.header("Equation Solver")
    st.write("Example: x**2 - 4 = 0")
    expr = st.text_input("Enter equation:")
    var = st.text_input("Enter variable to solve for (e.g., x):")
    if st.button("Solve Equation"):
        try:
            x = symbols(var)
            equation = Eq(eval(expr.replace("=", "-")), 0)
            sol = solve(equation, x)
            st.success(f"Solutions: {sol}")
        except Exception as e:
            st.error(f"Error: {e}")