<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
.page1 {
border: 1px dashed red;
60%;
height: 600px;
text-align: center;
font-size: 0;
}
.page1:before {
content: '.';
display: inline-block;
vertical-align: middle;
text-align: center;
height: 100%;
}
.page2 {
vertical-align: middle;
display: inline-block;
font-size: 18px;
}
</style>
</head>
<body>
<div class="page1">
<span class="page2">中中中<br>中中中中中中中中中中中中中</span>
</div>
</body>
</html>