#toc_container { color: #000; background-color: #f90; background-image: url("images/menu-bg02.gif"); text-align: left; width: 800px }
#toc_container ul,#toc_container li{
  list-style:none;
  margin:0;
  padding:0;
}

  #root_toc li,
  #root_toc li a
   { font-size: 12px; width: 195px }
  
  #root_toc li { float: left }

  #root_toc li.plist ul{
    display:none;
    position:absolute;
  }
  #root_toc li.plist:hover  > a
  {
    background-color:#f60;
  }
  #root_toc li.plist:hover ul{
    display: block;
    /* 縦にする場合は次の指定を使う
    margin-left:90px;
    margin-top:-25px;
    */
  }
    #root_toc li.plist li{
      float:none;
      display:list-item;
    }
  #root_toc li a { color: #555; line-height: 2.8; text-decoration: none; background-image: url("images/menu-bg02.gif"); text-indent: 2em; display: block }
#root_toc li.ilist a { color: #555; line-height: 2.5; text-decoration: none; background-image: url("images/menu-bg02.gif"); text-indent: 2em; display: block }
#root_toc li a:hover
   { color: #fff; background-color: #fff; background-image: url("images/menu-bg03.gif") }
#root_toc li a.current { color: #fff; background-color: #fff; background-image: url("images/menu-bg03.gif") }