今天想要分享另一個我在 Youtube 上面看到的教學，
是個眼球會隨著你的滑鼠移動的小練習，
影片連結在此。

覺得 JS 有好多種 X、Y，
常常記不起來各是指什麼樣的距離，
之後有機會再來好好整理一番，
以下一樣分享我寫的程式碼。

效果

HTML

<div class="face">
  <div class="eyes">
    <div class="eye"></div>
    <div class="eye"></div>
  </div>
</div>

CSS

* {
  padding: 0;
  margin: 0;
  list-style: none;
}

body {
  height: 100vh;
  display: flex;
  align-items: center;
  background-color: #95a5a6;
}

.face {
  width: 400px;
  height: 400px;
  margin: auto;
  background-color: #f1c40f;
  border-radius: 50%;
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  box-shadow: 0 0 20px 10px rgba(0, 0, 0, .2);
}

.face::after {
  content: '';
  position: absolute;
  width: 210px;
  height: 100px;
  background-color: #c0392b;
  left: 0;
  right: 0;
  margin: auto;
  bottom: 50px;
  border-radius: 0 0 100px 100px;
  transition: .5s;
}

.face:hover::after {
  bottom: 80px;
  height: 40px;
  border-radius: 0;
}

.eyes {
  display: flex;
  position: relative;
  top: -60px;
}

.eye {
  width: 120px;
  height: 120px;
  margin: 15px;
  background-color: #fff;
  border-radius: 50%;
  position: relative;
}

.eye::before {
  content: '';
  position: absolute;
  width: 60px;
  height: 60px;
  background-color: #222;
  border-radius: 50%;
  top: 50%;
  left: 25%;
  transform: translate(-50%, -50%);
}

JS

document.querySelector('body').addEventListener('mousemove', eyeballMove);

function eyeballMove() {
  const eye = document.querySelectorAll('.eye');
  eye.forEach(eye => {
    let x = eye.getBoundingClientRect().left + eye.clientWidth / 2;
    let y = eye.getBoundingClientRect().top + eye.clientHeight / 2;
    let rad = Math.atan2(event.pageX - x, event.pageY - y);
    let rot = -rad * 180 / Math.PI + 270;
    eye.style.transform = `rotate(${rot}deg)`;
  })
}

今天就先到這裡啦～
我們明天見。