W3School TIY
编辑您的代码：
<html> <head> <style type="text/css"> .important {color:red;} </style> </head> <body> <h1 class="important">This heading is very important.</h1> <p class="important">This paragraph is very important.</p> <p>This is a paragraph.</p> <p>This is a paragraph.</p> <p>This is a paragraph.</p> <p>...</p> </body> </html>
查看结果: