1 Embedded, written directly into the web page
<style type="text/css"> css样式 如: p{ color:red;}</style>
2. Link type
<style href="..../xx.css" type="text/css"> </style>
3. Introduction
<style type="text/css"> @import url(.../xxx.css) </style>
4. Write directly into the html content
<元素 algin=“center/right”> </元素>