<!DOCTYPE html>
<html>
    <head>
        <meta charset=utf-8>
        <style type="text/css">
            * {
                margin: 0;
                padding: 0;
            }
            .outer {
                width: 100px;
                height: 100px;
                background-color: black;
                position:relative;
            }
            .inner {
                width: 80px;
                height: 80px;
                background-color: red;
                left:10px;
                position:inherit;//从父元素继承定位属性
            }
        </style>
    </head>
    <body>
    	<section class="outer">
            <section class="inner">
                
            </section>
        </section>
    </body>
</html>

考察：

  1. 定位中的继承属性