W3School TIY
编辑您的代码：
<html> <head> <style type="text/css"> img.normal { height: auto } img.big { height: 160px } img.small { height: 30px } </style> </head> <body> <img class="normal" src="../i/eg_smile.gif" /> <br /> <img class="big" src="../i/eg_smile.gif" /> <br /> <img class="small" src="../i/eg_smile.gif" /> </body> </html>
查看结果: