calculator.js

document.addEventListener("DOMContentLoaded", () => {
    const display = document.getElementById("display");
    const buttons = document.querySelectorAll(".btn");
    const themeSwitch = document.getElementById("theme-switch");
    const body = document.body;

    themeSwitch.addEventListener("change", () => {
        body.classList.toggle("dark");
    });

    buttons.forEach(button => {
        button.textContent = button.getAttribute("data-value");

        button.addEventListener("click", () => {
            const value = button.getAttribute("data-value");
            if (value === "C") {
                display.textContent = "0";
            } else if (value === "DEL") {
                display.textContent = display.textContent.slice(0, -1);
            } else if (value === "=") {
                try {
                    display.textContent = eval(display.textContent);
                } catch {
                    display.textContent = "Error";
                }
            } else {
                if (display.textContent === "0") {
                    display.textContent = value;
                } else {
                    display.textContent += value;
                }
            }
        });
    });
});