在page_header.lbi中加入

<script type="text/javascript">
if (screen.width < 1280)
{
document.write("<link href='themes/yufu/style.css' rel='stylesheet' type='text\/css'\/>");
}
else {
document.write("<link href='themes/yufu/style_1024.css' rel='stylesheet' type='text\/css'\/>");
}
</script>