盒子垂直居中，水平居中实现例子
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<div></div>
</body>
</html>
<style>
body {
margin: 0;
}
div {
position: absolute;
width: 200px;
height: 200px;
left: 50%;
top: 50%;
margin-left: -100px;
margin-top: -100px;
background-color: red;
}
</style>
可以使用更简单的方式
div {
position: absolute;
width: 200px;
height: 200px;
left: 50%;
top: 50%;
transform: translate(-50%, -50%);
background-color: red;
}
标签：居中,top,50%,position,margin,css,200px From： https://www.cnblogs.com/dming4/p/17573198.html