<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
li {
width: 200px;
height: 200px;
margin: 20px;
float: left;
list-style: none;
text-align: center;
font: 50px/200px 'simsun';
background-color: pink;
}
</style>
<script src="jquery-3.4.1.js"></script>
<script>
$(document).ready(function () {
$('ul li').each(function (index, el) {
$(el).css('opacity', (index+1)/10);
})
})
</script>
</head>
<body>
<ul>
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
<li>5</li>
<li>6</li>
<li>7</li>
<li>8</li>
<li>9</li>
<li>10</li>
</ul>
</body>
</html>
