<header>
  <h2 class="title">MouseEvent -> pageY</h2>
  <p class="description">Визначає вертикальну позицію миші відносно сторінки.</p>
</header>
<main>
  <button id="toggleFollow">Вмикнути слідування</button>
  <div class="result">
    <div id="followerBox"></div>
  </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;
  height: 300px;
  position: relative;
  overflow: hidden;
  -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);
}

#followerBox {
  width: 30px;
  height: 30px;
  background-color: #4CAF50;
  position: absolute;
  left: 50%;
  transform: translate(-50%, -50%);
  border-radius: 4px;
}

button {
  margin-bottom: 15px;
  padding: 10px;
  cursor: pointer;
}

const toggleFollowBtn = document.getElementById('toggleFollow');
const followerBox = document.getElementById('followerBox');
let isFollowing = false;

toggleFollowBtn.addEventListener('click', () => {
  isFollowing = !isFollowing;
  toggleFollowBtn.textContent = isFollowing ? 'Вимкнути слідування' : 'Вмикнути слідування';
});

document.addEventListener('mousemove', (event) => {
  if (isFollowing) {
    let yPos = event.pageY - followerBox.offsetHeight / 2;
    followerBox.style.top = `${yPos}px`;
  }
});

External CSS

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External JavaScript

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