from flask import Flask, render_template, request
app = Flask(__name__)
@app.route("/")
def home():
    return render_template("index.html")
@app.route("/calculate", methods=["POST"])
def calculate():
    units = int(request.form["units"])
    bill = units * 5
    if units <= 100:
        message = "Great! You are an energy saver! 🌱"
    elif units <= 200:
        message = "Not bad! Try saving a little more! 👍"
    else:
        message = "Whoa! Time to switch off some lights! 💡"
    return render_template("index.html", units=units, bill=bill, message=message)

if __name__ == "__main__":
    app.run(debug=True)