<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>position & transform: translate(-50%, -50%) 实现块元素百分比下居中</title>
<style>
html,body {
width: 100%;
height: 100%;
position: relative;
}
.box {
width: 800px;
height: 500px;
background-color: #FFD914;
}
.inside {
width: 60%;
height: 30%;
background-color: red;
}
.center {
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
}
</style>
</head>
<body>
<div class="box center">
<div class="inside center"></div>
</div>
</body>
</html>