HTML代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
* {
padding: 0;
margin: 0;
}
.div-container {
width: 800px;
}
.item {
float: left;
width: 20%;
height: 100px;
background-color: red;
}
/*
选中最后一行
*/
.item:nth-last-child(6) ~ div {
background-color: #61F5E9;
}
</style>
</head>
<body>
<div class="div-container">
<div class="item">1</div>
<div class="item">2</div>
<div class="item">3</div>
<div class="item">4</div>
<div class="item">5</div>
<div class="item">6</div>
<div class="item">7</div>
<div class="item">8</div>
<div class="item">9</div>
<div class="item">10</div>
</div>
</body>
</html>
效果图：
