css-三边框,外边距和内边距

<div style="width:100px;height:50px;border: solid black 1px;position: absolute;right: 500px; bottom:200px;"></div><!-- 绘制一个1像素的黑色实现边框 -->
<div style="width:100px;height:50px;border: dotted red 3px;position: absolute;right: 500px; bottom:300px;"></div><!-- 绘制一个3像素的红色电线边框 -->
<div style="border-top-right-radius: 50px;background-color:#9C27B0;border-left-color: gray;border-top-width: 5px;width:100px;height:50px;position: absolute;right: 500px; bottom:400px;"></div><!-- 绘制一个3像素的红色电线边框 -->

来源：https://www.cnblogs.com/tingbogiu/p/5530154.html