SW.js

let intervalId;
let hours = 0, minutes = 0, seconds = 0;

document.getElementById("startBtn").addEventListener("click", startTimer);
document.getElementById("stopBtn").addEventListener("click", stopTimer);
document.getElementById("resetBtn").addEventListener("click", resetTimer);

function updateDisplay() {
  document.getElementById("hours").innerText = String(hours).padStart(2, '0');
  document.getElementById("minutes").innerText = String(minutes).padStart(2, '0');
  document.getElementById("seconds").innerText = String(seconds).padStart(2, '0');
}

function startTimer() {
  if (intervalId) return; 
  intervalId = setInterval(() => {
    seconds++;
    if (seconds === 60) {
      seconds = 0;
      minutes++;
    }
    if (minutes === 60) {
      minutes = 0;
      hours++;
    }
    updateDisplay();
  }, 1000);
}

function stopTimer() {
  clearInterval(intervalId);
  intervalId = null;
}

function resetTimer() {
  clearInterval(intervalId);
  intervalId = null;
  hours = minutes = seconds = 0;
  updateDisplay();
}