<style>
.div{
display: flex;
flex-wrap: wrap;
justify-content: space-around;
}
.div>div{
width: 46%;
height: 50px;
border: 1px red solid;
box-sizing: border-box;
line-height: 50px;
text-indent: 30px;
}
.div>div:nth-child(4n-2){
background-color: red;
}
.div>div:nth-child(4n-3){
background-color: red;
}
</style>
<body>
<div class="div">
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
</div>
</body>
效果：
image.png
