<!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>
.box {
display: flex;
flex-wrap: wrap;
justify-content: space-around;
}
.item {
width: calc(calc(100% / 3) - 10px);
border: 1px solid blue;
height: 30px;
line-height: 30px;
color: red;
margin-bottom: 10px;
}
.item:nth-child(n+4) {
margin-bottom: 0;
}
</style>
</head>
<body>
<div class="box">
<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>
</body>
</html>
标签：flex,bottom,布局,height,wrap,calc,30px From： https://www.cnblogs.com/whlBooK/p/17513888.html