<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style>
body,html{
height: 100%;
padding: 0;
margin: 0;
}
.parent{
height: 80%;
position: relative;
background-color: #007AFF;
}
.son{
500px;
*height:expression(this.parentNode.offsetHeight + "px");
background-color: yellow;
position: absolute;
top: 0;
bottom: 0;
}
</style>
</head>
<body>
<div class="parent">
<div class="son">son</div>
</div>
</body>
</html>