无法水平制作垂直菜单

Question

我不能让我的垂直菜单水平移动。请帮助，因为我试图左右浮动ul并尝试内联无。我不太确定我对哪个类应该放入内联或浮动而感到困惑。提前感谢大家对此的帮助，因为这个一直在疯狂，我确信这是一个简单的解决方案，但我无法看到它。

/* define a fixed width for the entire menu */

.horiz_nav {
  width: 100px;
  float: right;
}


/* reset our lists to remove bullet points and padding */

.mainmenu_horiz {
  list-style: none;
  padding: 0;
  margin: 0;
}

.mainmenu_horiz ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.menu_horiz li {
  list-style: none;
  padding: 0;
  margin: 0;
  display: inline-block;
  float: right;
}


/* make ALL links (main and submenu) have padding and background color */

.mainmenu_horiz a {
  display: block;
  background-color: #8EC752;
  text-decoration: none;
  padding: 10px;
  color: #000;
}


/* add hover behaviour */

.mainmenu_horiz a:hover {
  background-color: #ABD281;
}


/* when hovering over a .mainmenu item,
      display the submenu inside it.
      we're changing the submenu's max-height from 0 to 200px;
    */

.mainmenu_horiz li:hover .submenu_horiz {
  display: block;
  max-height: 200px;
}


/*
      we now overwrite the background-color for .submenu links only.
      CSS reads down the page, so code at the bottom will overwrite the code at the top.
    */

.submenu_horiz a {
  background-color: #999;
}


/* hover behaviour for links inside .submenu */

.submenu_horiz a:hover {
  background-color: #666;
}


/* this is the initial state of all submenus.
      we set it to max-height: 0, and hide the overflowed content.
    */

.submenu_horiz {
  overflow: hidden;
  max-height: 0;
  -webkit-transition: all 0.5s ease-out;
}

<header class="header" id="header">
  <div id="horiz_nav" class="horiz_nav">
    <ul class="mainmenu_horiz">
      <li><a href="">Home</a></li>
      <li><a href="">Courses</a>
        <ul class="submenu_horiz">
          <li><a href="">Motor Learning</a></li>
          <li><a href="">MS II</a></li>
        </ul>
      </li>
    </ul>
  </div>
</header>

Answer 1

首先，.menu_horiz li应该是.mainmenu_horiz li，然后这应该有float: left，不对，加上它不需要浮动*和* display: inline-block - 这两个中的一个就足够了。

.mainmenu_horiz li{
  list-style: none;
  padding: 0;
  margin: 0;    
  float: left;
}

Answer 2

/ *我刚刚把你的css改成了这个。只需检查它是否适合您。 * /

ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-color: #333;
}

li {
    float: left;
}