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 #nav ul{ margin-bottom:5px;} 
 #nav strong{ color:#696;} 
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 #nav.dyn li ul.show{ display:block;} 
 #nav.dyn li{ padding-left:15px;} 
 #nav.dyn li.parent{ background:url(images/user_23.gif) 5px 10px no-repeat;} 
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<h2>js實(shí)現(xiàn)無(wú)限級(jí)樹(shù)形導(dǎo)航列表</h2>
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   </ul> 
   </li> 
   <li><a href="#">小類(lèi)別二</a></li> 
  </ul> 
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 <ul> 
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 </ul> 
 </li> 
</ul>