script.js

const display = document.getElementById("display");
const buttons = document.querySelectorAll("button");

buttons.forEach(button => {
    button.addEventListener("click", () => {
        let value = button.innerText;

        if (value === "C") {
            display.innerText = "0";
        } 
        else if (value === "=") {
            try {
                // Replace symbols before eval
                let expression = display.innerText
                    .replace(/×/g, "*")
                    .replace(/÷/g, "/")
                    .replace(/−/g, "-");

                display.innerText = eval(expression);
            } catch {
                display.innerText = "Error";
            }
        } 
        else {
            if (display.innerText === "0") {
                display.innerText = value;
            } else {
                display.innerText += value;
            }
        }
    });
});

// Keyboard Support
document.addEventListener("keydown", (e) => {
    if ((e.key >= '0' && e.key <= '9') || "+-*/.%".includes(e.key)) {
        if (display.innerText === "0") {
            display.innerText = e.key;
        } else {
            display.innerText += e.key;
        }
    }
    else if (e.key === "Enter") {
        try {
            display.innerText = eval(display.innerText);
        } catch {
            display.innerText = "Error";
        }
    }
    else if (e.key === "Backspace") {
        display.innerText = display.innerText.slice(0, -1) || "0";
    }
    else if (e.key.toLowerCase() === "c") {
        display.innerText = "0";
    }
});