script.js

const minutesEl = document.querySelector("#minutes");
const secondsEl = document.querySelector("#seconds");
const millisecondsEl = document.querySelector("#milliseconds");
const startBtn = document.querySelector("#startBtn");
const pauseBtn = document.querySelector("#pauseBtn");
const resumeBtn = document.querySelector("#resumeBtn");
const resetBtn = document.querySelector("#resetBtn");

let interval;
let minutes = 0;
let seconds = 0;
let milliseconds = 0;
let isPaused = false;

startBtn.addEventListener("click", startTimer)
pauseBtn.addEventListener("click", pauseTimer)
resumeBtn.addEventListener("click", resumeTimer)
resetBtn.addEventListener("click", resetTimer)

function startTimer() {

    interval = setInterval(() => {
        if (!isPaused) {

            milliseconds += 10;

            if (milliseconds === 1000) {
                seconds++;
                milliseconds = 0;
            }

            if (seconds === 60) {
                minutes++;
                seconds = 0;
            }

            minutesEl.textContent = formatTime(minutes);
            secondsEl.textContent = formatTime(seconds);
            millisecondsEl.textContent = formatMilliseconds(milliseconds);
        }
    }, 10);

    startBtn.style.display = "none"
    pauseBtn.style.display = "block"
}

function pauseTimer() {
    isPaused = true
    pauseBtn.style.display = "none"
    resumeBtn.style.display = "block"
}

function resumeTimer() {
    isPaused = false
    pauseBtn.style.display = "block"
    resumeBtn.style.display = "none"
}

function resetTimer() {
    clearInterval(interval);
    minutes = 0;
    seconds = 0;
    milliseconds = 0;

    minutesEl.textContent = "00";
    secondsEl.textContent = "00";
    millisecondsEl.textContent = "000";

    startBtn.style.display = "block";
    pauseBtn.style.display = "none";
    resumeBtn.style.display = "none";
}

function formatTime(time) {
    return time < 10 ? `0${time}` : time;
}

    function formatMilliseconds(time) {
        return time < 100 ? `{time}`.padStart(3, "0") : time;
}