css - CSS 中的下拉菜单出现在页面内容下方

Question

我已经对这个问题进行了数小时的研究，但无法让它发挥作用！我终于让我的 CSS 菜单看起来完全符合我的要求 - 耶！但现在它在页面上的其他内容下下降，我不知道如何让它出现在顶部。我已经调整了很多人提到的定位，并将z-index设置一直设置到2000，没有效果。我究竟做错了什么？？使用 Firefox - 当前版本。

这是 CSS 代码（不，我没有显示示例的链接，因为该站点尚未发布）

    #cssmenu:before, #cssmenu:after, #cssmenu > ul:before, #cssmenu > ul:after {

    content: '';
    display: table;

}


#cssmenu:after, #cssmenu > ul:after {

    clear: both;

}
#cssmenu
{
    zoom: 1;
}

#cssmenu > ul
{
    background: #00305f;
    margin: 0;
    padding: 0;
    position: relative;
}

#cssmenu > ul li
{
    margin: 0;
    padding: 0;
    list-style: none;

}

#cssmenu > ul > li
{
    float: left;
    position: relative;
}

#cssmenu > ul > li > a
{
    padding: 20px 25px;
    display: block;
    color: white;
    font-family: Georgia, Times, Serif;
    font-size: 20px;
    text-transform: capitalize;
    text-decoration: none;
    text-shadow: 0 -1px 0 rgba(151, 99, 33, .43);
    line-height: 18px;
}

#cssmenu > ul > li:hover > a
{
    background: #5783af;

}

#cssmenu > ul > li > a > span
{
    line-height: 18px;
}

#cssmenu > ul > li.active > a
{
    background: #5783af;
}

#cssmenu > ul > li > a:active
{
    background: #5783af;
}

#cssmenu > ul ul
{
    opacity: 0;
    visibility: hidden;
    position: absolute;
    top: 120px;
    background: #00305f;
    margin: 0;
    padding: 0;
    z-index: 2000;
    -webkit-transition: all .35s .2s ease-in-out;
    -moz-transition: all .35s .2s ease-in-out;
    -ms-transition: all .35s .2s ease-in-out;
    transition: all .35s .2s ease-in-out;
}

#cssmenu > ul li:hover ul
{
    opacity: 1;
    visibility: visible;
    margin: 0;
    color: #5783af;
    z-index: 2000;
    top: 64px;
    left: 0;
}

#cssmenu > ul ul:before
{
    content: '';
    position: absolute;
    top: -10px;
    width: 100%;
    height: 16px;
    background: transparent;
}

#cssmenu > ul ul li
{
    list-style: none;
    padding: 0;
    margin: 0;
    width: 100%;
}

#cssmenu > ul ul li a
{
    padding: 12px 20px;
    display: block;
    color: white;
    font-family: Georgia, Times, Serif;
    font-size: 16px;
    text-transform: capitalize;
    text-decoration: none;
    width: 175px;
    border-left: 4px solid transparent;
    -webkit-transition: all .35s ease-in-out;
    -moz-transition: all .35s ease-in-out;
    -ms-transition: all .35s ease-in-out;
    transition: all .35s ease-in-out;
    text-shadow: 0 -1px 0 rgba(151, 99, 33, .43);
}

#cssmenu > ul ul li a:hover
{
    border-left: 4px solid #055988;
    background: #5783af;
}

#cssmenu > ul ul li a:active
{
    background: #5783af;
}

HTML 代码：

<div id='cssmenu'>
<ul>
   <li class='has-sub'><a href='home.html'><span>Home</span></a>
  <ul>
         <li><a href='resources.html'><span>Resources</span></a></li>
    <li><a href='products.html'><span>Products</span></a></li>
    <li class='last'><a href='contact.html'><span>Contact Us</span></a></li>
      </ul>
  </li>
   <li class='has-sub'><a href='health-wellness.html'><span>Health & Wellness</span></a>
      <ul>
         <li><a href='cooking-from-scratch.html'><span>Cooking From Scratch</span></a></li>
         <li><a href='sustainable-gardening.html'><span>Sustainable Gardening</span></a></li>
         <li><a href='csa.html'><span>Community Supported Agriculture</span></a></li>
         <li><a href='fun-ways-to-exercise.html'><span>Fun Ways to Exercise</span></a></li>
         <li><a href='pain-relief.html'><span>Natural Relief for Chronic Pain</span></a></li>
         <li class='last'><a href='toxic-load.html'><span>Reducing Your Toxic 

Load</span></a></li>
      </ul>
   </li>
   <li><a href='relationships.html'><span>Relationships</span></a></li>
   <li><a href='wealth.html'><span>Wealth</span></a></li>
   <li class='last'><a href='spirituality.html'><span>Spirituality</span></a></li>
</ul>
</div>

Answer 1

尝试：

    #cssmenu
{
    zoom: 1;
z-index:9999 !important;
}