<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.box{
width: 300px;
height: 300px;
background-color: gray;
position:relative; //针对position定位时存在
}
.box1{
display: table-cell;
vertical-align: middle;
text-align: center;
}
.box2{
display: flex;
justify-content:center;
align-items:Center;
}
.box3 div{
width: 50%;
height: 50%;
background:
overflow: auto;
margin: auto;
position: absolute;
top: 0; left: 0; bottom: 0; right: 0;
}
.box4 div{
position: absolute;
top:50%;
left:50%;
width:100%;
transform:translate(-50%,-50%);
text-align: center;
}
</style>
</head>
<body>
<div class="box box1">
<!--<span>垂直居中</span>-->
<div>垂直居中</div>
</div>
<div class="box box2">
<!--<span>垂直居中</span>-->
<div>垂直居中</div>
</div>
<div class="box box3">
<!--<span>垂直居中</span>-->
<div>垂直居中</div>
</div>
<div class="box box4">
<!--<span>垂直居中</span>-->
<div>垂直居中</div>
</div>
</body>
</html>
