css 圆角效果

http://intacto10years.com/index_start.php
<div style="width:800px; height:1300px;">
<div style="width:800px; height:40px; background-color:#FF0000; position:fixed; z-index:5000;">头部不动</div>

<h1>圆角效果</h1>
<div style="background-color:#00FF00; width:100px; height:100px; border-radius:7px 7px 7px 7px"></div>
</div>