app.py

import streamlit as st

st.set_page_config(page_title="BMI Calculator", page_icon="💪", layout="centered")

st.title('💪 BMI Calculator')

st.write('Calculate your Body Mass Index (BMI) easily!')

# Input
weight = st.number_input('Enter your weight (kg)', min_value=1.0, step=0.5)
height = st.number_input('Enter your height (meters)', min_value=0.1, step=0.01)

# Calculate
if st.button('Calculate'):
    if height > 0:
        bmi = weight / (height ** 2)
        st.success(f'Your BMI is: {bmi:.2f}')
        
        # Category
        if bmi < 18.5:
            st.info('You are Underweight.')
        elif 18.5 <= bmi < 24.9:
            st.success('You have Normal weight.')
        elif 25 <= bmi < 29.9:
            st.warning('You are Overweight.')
        else:
            st.error('You are Obese.')
    else:
        st.error('Height must be greater than zero.')