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

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

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

}

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

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

    startBtn.style.display ("click", startTime)
    pauseBtn.style.display  ("click", pauseTimer)
    resumeBtn.style.display ("click", resumeTimer) 
    resetBtn.style.display  ("click", resetTimer)
}