ul跑到div外面了，样式定不了

Question

css:
#producttype {height:360px;padding-left:50px;}
#producttype ul{font-size:11pt;list-style:none;}
#producttype li{float:left; width:200px; height:40px; line-height:40px; text-indent:10px; _display:inline; z-index:998;display:inline}
#producttype div{background-color:Red;width:100%;}html:
<div id="producttype">
    <div>1大类<br />
         <ul><li><a href="issue-1-1.shtml">数学</a></li><li><a href="issue-1-2.shtml">物理</a></li></ul>
    </div><br />
    <div>2大类<br />
         <ul><li><a href="issue-1-219.shtml">语文</a></li><li><a href="issue-1-220.shtml">英语</a></li></ul>
    </div>
</div>

Answer 1

html 更改
<div id="producttype">
    <div>1大类<br />
         <ul><li><a href="issue-1-1.shtml">数学</a></li><li><a href="issue-1-2.shtml">物理</a></li></ul><div style=" clear:both"></div>
    </div><br />
    <div>2大类<br />
         <ul><li><a href="issue-1-219.shtml">语文</a></li><li><a href="issue-1-220.shtml">英语</a></li></ul><div style=" clear:both"></div>
    </div>
    
</div>