W3School TIY
编辑您的代码：
<html> <head> <style type="text/css"> h1 {font-size: 300%} h2 {font-size: 200%} p {font-size: 100%} </style> </head> <body> <h1>This is header 1</h1> <h2>This is header 2</h2> <p>This is a paragraph</p> </body> </html>
查看结果: