<header>
  <h2 class="title">Date.prototype.getSeconds()</h2>
  <p class="description">Використання методу для створення таймера.</p>
</header>
<main>
  <div class="result">
    <button onclick="startTimer()">Старт</button>
    <button onclick="stopTimer()">Стоп</button>
    <button onclick="resetTimer()">Перезапустити</button>
    <p>Минуло секунд: <span id="secondsElapsed">0</span></p>
  </div>
</main>

body {
  font-size: 16px;
  line-height: 1.5;
  font-family: monospace;
}

header {
  background-color: #f1f1f1;
  margin-bottom: 25px;
  padding: 15px;
  -webkit-box-shadow: 0px 0px 3px 0px rgba(118, 118, 118, 1);
  -moz-box-shadow: 0px 0px 3px 0px rgba(118, 118, 118, 1);
  box-shadow: 0px 0px 3px 0px rgba(118, 118, 118, 1);
}

header h2.title {
  padding-bottom: 15px;
  border-bottom: 1px solid #999;
}

header p.description {
  font-style: italic;
  color: #222;
}

.result {
  background-color: #f8f8f8;
  padding: 15px;
  -webkit-box-shadow: 0px 0px 3px 0px rgba(118, 118, 118, 1);
  -moz-box-shadow: 0px 0px 3px 0px rgba(118, 118, 118, 1);
  box-shadow: 0px 0px 3px 0px rgba(118, 118, 118, 1);
}

button {
  background-color: #4CAF50;
  border: none;
  color: white;
  padding: 10px 20px;
  text-align: center;
  display: inline-block;
  margin: 4px 2px;
  cursor: pointer;
  border-radius: 4px;
}

button:disabled {
  background-color: #ccc;
  cursor: not-allowed;
}

let timer;
let seconds = 0;

function startTimer() {
    document.querySelector('button[onclick="startTimer()"]').disabled = true;
    timer = setInterval(() => {
        seconds++;
        document.getElementById('secondsElapsed').textContent = seconds;
    }, 1000);
}

function stopTimer() {
    clearInterval(timer);
    document.querySelector('button[onclick="startTimer()"]').disabled = false;
}

function resetTimer() {
    clearInterval(timer);
    seconds = 0;
    document.getElementById('secondsElapsed').textContent = seconds;
    document.querySelector('button[onclick="startTimer()"]').disabled = false;
}

External CSS

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External JavaScript

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