CSS下拉导航栏导致以下内容移动

Question

css悬停下拉菜单在新页面上可以正常工作，但是在粘贴到与引导程序链接的html页面上时不起作用（我隐藏了其他css页面，所以我发现了导致问题的引导程序！）

因此，我使用devtool从“下拉列表内容”中隐藏了“ position：absolute”，但是下面的容器向下跳跃：http://prntscr.com/lu7frm

代码如下：

.navbar {
  overflow: hidden;
/*  background-color: #333;*/
  font-family: Arial, Helvetica, sans-serif;
}

.navbar a {
  float: right;
  font-size: 16px;
  color: #060606;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
}

.dropdown {
  float: right;
  overflow: hidden;
}

.dropdown .dropbtn {
  font-size: 16px;  
  border: none;
  outline: none;
  color: #060606;
  padding: 14px 16px;
  background-color: inherit;
  font-family: inherit;
  margin: 0;
}

.navbar a:hover, .dropdown:hover .dropbtn {
color:#4389dc;
transition:.3s ease-out;
}

.dropdown-contents {
  display: none;
  position: absolute;
  background-color: #f9f9f9;
  min-width: 160px;
  box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
  z-index: 1;
}

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

.dropdown-contents a:hover {
  background-color: #ddd;
}

.dropdown:hover .dropdown-contents {
  display: block;
}
/*navbar*/
#slapper {
    min-height: 2%;
    height: auto !important;
    height: 100%;

}

<link href="https://stackpath.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
<div class="container" style="padding:0px;">
<div class="navbar">
<a href="#home">For Professionals</a>
<a href="#home">Tax News</a>
  <a href="#home">Ask a Question</a>
  <a href="#news">Find an Accountant </a>
  <div class="dropdown">
    <button class="dropbtn">Learn About Taxes 
      &nbsp;&nbsp;<i class="fa fa-caret-down"></i>
    </button>
    <div class="dropdown-contents">
      <a href="#">Link 1</a>
      <a href="#">Link 2</a>
      <a href="#">Link 3</a>
    </div>
  </div> 
</div>
</div>

Answer 1

您需要从代码{overflow:hidden和.navbar中删除.dropdown才能看到下拉菜单。您不再需要它们清除浮点数，因为引导程序已经在执行此操作了。

.navbar {
  font-family: Arial, Helvetica, sans-serif;
  border-color:#000!important; /*to show that the height is good*/
}

.navbar a {
  float: right;
  font-size: 16px;
  color: #060606;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
}

.dropdown {
  float: right;
}

.dropdown .dropbtn {
  font-size: 16px;  
  border: none;
  outline: none;
  color: #060606;
  padding: 14px 16px;
  background-color: inherit;
  font-family: inherit;
  margin: 0;
}

.navbar a:hover, .dropdown:hover .dropbtn {
color:#4389dc;
transition:.3s ease-out;
}

.dropdown-contents {
  display: none;
  position: absolute;
  background-color: #f9f9f9;
  min-width: 160px;
  box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
  z-index: 1;
}

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

.dropdown-contents a:hover {
  background-color: #ddd;
}

.dropdown:hover .dropdown-contents {
  display: block;
}
/*navbar*/
#slapper {
    min-height: 2%;
    height: auto !important;
    height: 100%;

}

<link href="https://stackpath.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
<div class="container" style="padding:0px;">
<div class="navbar">
<a href="#home">For Professionals</a>
<a href="#home">Tax News</a>
  <a href="#home">Ask a Question</a>
  <a href="#news">Find an Accountant </a>
  <div class="dropdown">
    <button class="dropbtn">Learn About Taxes 
      &nbsp;&nbsp;<i class="fa fa-caret-down"></i>
    </button>
    <div class="dropdown-contents">
      <a href="#">Link 1</a>
      <a href="#">Link 2</a>
      <a href="#">Link 3</a>
    </div>
  </div> 
</div>
</div>