顶部导航栏CSS问题：下拉菜单被遮挡及退出按钮右移需求

问题说明 #

1. 下拉菜单被Radzen网格表头遮挡，调整z-index无效，需提升显示优先级
2. 退出按钮需单独向右对齐

修改后的CSS代码 #

ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background-color: #333;
  /* 添加定位与层级，确保导航栏整体优先级高于Radzen组件 */
  position: relative;
  z-index: 9999;
}

li {
  float: left;
}

/* 新增右浮动类，用于退出按钮 */
li.float-right {
  float: right;
}

li a,
.dropbtn {
  display: inline-block;
  color: white;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
}

li a:hover,
.dropdown:hover .dropbtn {
  background-color: red;
}

li.dropdown {
  display: inline-block;
}

.dropdown-content {
  display: none;
  position: fixed;
  background-color: #f9f9f9;
  min-width: 160px;
  box-shadow: 0px 8px 16px 0px rgba(0, 0, 0, 0.2);
  /* 进一步提高下拉菜单层级，确保不被遮挡 */
  z-index: 10000;
  overflow: visible;
}

.dropdown-content a {
  color: black;
  padding: 12px 16px;
  text-decoration: none;
  display: block;
  text-align: left;
}

.dropdown-content a:hover {
  background-color: #f1f1f1;
}

.dropdown:hover .dropdown-content {
  display: block;
}

修改后的HTML代码 #

<ul>
  <AuthorizeView Context="PageRights" Roles="Administrator">
    <Authorized>
      <li><a href="">Site client</a></li>
      <li><a href="Schedule">Horaire</a></li>
      <li><a href="Customers">Clients</a></li>
      <li class="dropdown">
        <a href="javascript:void(0)" class="dropbtn">Activités</a>
        <div class="dropdown-content">
          <a href="ActivityRequests">Activités</a>
          <a href="ActivityRequestCustomers">Demandes clients</a>
        </div>
      </li>
      <li><a href="ManualBilling">Ventes manuelles</a></li>
      <li class="dropdown">
        <a href="javascript:void(0)" class="dropbtn">Facturation</a>
        <div class="dropdown-content">
          <a href="Quotes">Soumissions</a>
          <a href="Payments">Paiements</a>
          <a href="PaidTaxes">Taxes perçues</a>
        </div>
      </li>
      <li class="dropdown">
        <a href="javascript:void(0)" class="dropbtn">Animaux</a>
        <div class="dropdown-content">
          <a href="Species">Animals</a>
          <a href="ACIAInfos">Informations ACIA</a>
        </div>
      </li>
      <li><a href="Utilities">Utilitaires</a></li>
      <li><a href="Account/Manage">Compte</a></li>
      <!-- 给退出按钮的li添加右浮动类 -->
      <li class="float-right">
        <form action="Account/Logout" method="post">
          <AntiforgeryToken />
          <input type="hidden" name="ReturnUrl" value="" />
          <button type="submit" class="btn" style="background: transparent;border: none !important;color: white; height:53px">
                Déconnexion
            </button>
        </form>
      </li>
    </Authorized>
    <NotAuthorized>
      <li><a href="Account/Login">Connexion</a></li>
    </NotAuthorized>
  </AuthorizeView>
</ul>

修改说明 #

1. 下拉菜单层级修复：给导航栏ul设置position: relative和z-index: 9999，同时将下拉菜单dropdown-content的z-index提升至10000。之前调整z-index无效是因为父元素未设置定位，子元素层级无法突破父容器限制，现在整个导航栏的优先级高于Radzen网格表头，下拉菜单不会再被遮挡。
2. 退出按钮右对齐：新增float-right类并添加到退出按钮所在的li上，利用float: right让该元素单独靠右，其他菜单保持左浮动即可实现需求。

内容的提问来源于stack exchange，提问作者rose-marie paradis