如何使子菜单在我的导航中起作用？

如何解决如何使子菜单在我的导航中起作用？

我在CSS上遇到了一些问题， sub sub （第三，第四级）菜单不起作用，也无法使其起作用，我已经尝试了所有可以考虑的方法。请任何人有时间查看我的代码。我玩过代码，尝试了各种各样的事情，但是没有任何效果。

I tried with

.navigation-1 ul li ul li ul li

但找不到问题。我想我的CSS技能不好，大声笑：P

.navigation-1{
  float: left;
  width: auto;
  margin-right: 0px;
}

.navigation-1 ul > li{
  float: left;
  width: auto;
  position: relative;
}
.navigation-1 li:last-child{
  margin-right: 0px;
}
.navigation-1 ul > li > a{
  display: inline-block;
  padding: 26px 30px;
  font-size: 15px;
  text-transform: capitalize;
  /*font-family: 'Exo',sans-serif;*/
}
.navigation-1 > ul > li:after,.navigation-1 > ul > li:before{
  position: absolute;
  content: "";
  top:50%;
  left: 0px;
  bottom: 0px;
  height: 10px;
  width: 2px;
  margin: 15px auto 0px;
  right: 0px;
  opacity: 0;
}
.navigation-1 > ul > li:before{
  padding: 0px 5px;
  border-left: 2px solid #2f3539;
  border-right: 2px solid #2f3539;
  opacity: 0;
}
.navigation-1 > ul > li:after{
  border-right: 2px solid #2f3539;
  height: 15px;
  width: 2px;
  opacity: 0;
}
.navigation-1 ul li ul{
  position: absolute;
  left: 0px;
  right: 0px;
  top:100%;
  width: 195px;
  background: #171e22;
  visibility: hidden;
  opacity: 0;
  overflow: hidden;
  z-index: 9999;
}
.navigation-1 ul li ul li{
  float: left;
  width: 100%;
}
.navigation-1 > ul > li.active:after,.navigation-1 > ul > li.active:before,.navigation-1 > ul > li:hover:after,.navigation-1 > ul > li:hover:before{
  opacity: 1;
}
nav.navigation-1 ul li:hover ul{
  visibility: visible;
  opacity: 1;
} 
nav.navigation-1 ul li ul li a{
  border-bottom: 1px solid #2f3539;
  color: #fff;
  display: inline-block;
  padding:9px 15px;
  position: relative;
  width: 100%;
}
.navigation-1 ul li ul li:hover a{
  background: #dc1937;
  border-color: #dc1937;
  color:#fff !important;
}

<nav class="navigation-1">
   <ul>  
    <li class="active"><a href="index.html">home</a>
      <ul class="sub-menu children">
       <li><a href="light-index.html">Home Light</a></li>   
     </ul>
    </li>
    <li><a href="artist.html">artist</a>
      <ul class="sub-menu children">
        <li><a href="artist.html">artist</a></li>
        <li><a href="artist-blog.html">artist 02</a></li>
        <li><a href="event-organiser.html">artist 03</a></li>
        <li><a href="dj.html">dj</a></li>
      </ul> 
    </li>
    <li class="menu-item ">
      <a href="index.htm#">event</a>
      <ul class="sub-menu children">
        <li>
          <a href="event-list.html">event list</a>
        </li>
        <li>
          <a href="event-list-2.html">event list 02</a>
        </li>
        <li>
          <a href="event-list-3.html">event list 03</a>
        </li>
        <li>
          <a href="event-detail.html">event detail</a>
        </li>
      </ul>
    </li>
    <li class="menu-item "><a href="index.htm#">music</a>
      <ul class="sub-menu children">
        <li>
          <a href="dj.html">dj</a>
        </li>
        <li>
          <a href="video.html">video</a>
        </li>
        <li>
          <a href="video-list.html">video list</a>
        </li>
        <li>
          <a href="video-detail.html">video detail</a>
        </li>
        <li>
          <a href="mp3-list.html">mp3 list</a>
        </li>
        <li>
          <a href="music-artist-albums.html">music artist albums</a>
        </li>
        <li>
          <a href="music-albums.html">music albums</a>
        </li>
        <li>
          <a href="masonry-gallary.html">masonry gallary</a>
        </li>
      </ul>
    </li>
    <li class="menu-item "><a href="index.htm#">blog</a>
      <ul class="sub-menu children">
        <li>
          <a href="blog-detail.html">blog detail</a>
        </li>
        <li>
          <a href="blog-detail-leftsidebar.html">blog left sidebar</a>
        </li>
        <li>
          <a href="blog-right-sidebar.html">blog right sidebar</a>
        </li>
        <li>
          <a href="blog-full.html">blog full</a>
        </li>
        <li>
          <a href="blog-medium.html">blog medium</a>
        </li>
        <li>
          <a href="blog-small.html">blog small</a>
        </li>
        <li>
          <a href="masonry-blog.html">masonry small</a>
        </li>
      </ul>
    </li>
    <li class="menu-item ">
      <a href="index.htm">page</a>
      <ul class="sub-menu children">
        <li>
          <a href="shop.html">shop</a>
        </li>
        <li>
          <a href="shop-items.html">shop items</a>
        </li>
        <li>
          <a href="shop-listing.html">shop listing</a>
        </li>
        <li>
          <a href="headers.html">headers</a>
        </li>
      </ul>
    </li>
    <li><a href="contact-us.html">contact us</a></li>
  </ul>
</nav>  

这是原始的HTML代码（没有子子菜单，因为我已经通过CMS管理导航） 谢谢 R