Question

我正在尝试创建一个网页，手写了以下代码：

body {
  font-size: 16px;
  color: #fff;
  background-color: #4203A1;
  font-family: 'Roboto', sans-serif;
}

#header-nav {
  background-color: #8605E9;
  border-radius: 0;
  border: 3px solid black;
}

.navbar-brand h1 {
  font-size: 1.5em;
  margin-top: -8px;
  margin-bottom: 2px;
  font-weight: bold;
  text-transform: uppercase;
  line-height: 1.5;
  text-align: left;
}

.navbar-default .navbar-brand {
  color: #fff;
}

.dropdown-menu {
  width: 100%;
  text-align: center;
  margin-top: 53px;
  border: 1px solid black
}

.dropdown button {
  background-color: #fff;
}

.navbar-header button.navbar-toggle {
  clear: both;
  margin-top: -42px;
}

.heading {
  /*position: relative;*/
}

#menu-sections section {
  border: 3px solid black;
  margin: 20px;
  background-color: #607353;
}

.col-xs-12 p {
  padding: 10px;
  text-align: left;
}

.col-xs-12 h3 {
  color: #000000;
}

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
<link href="https://fonts.googleapis.com/css?family=Roboto" rel="stylesheet">
<script src="https://code.jquery.com/jquery-1.11.3.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.js"></script>

<body>
  <header>
    <nav id="header-nav" class="navbar navbar-default">
      <div class="container">
        <div class="navbar-header">
          <div class="navbar-brand navbar-left">
            <h1> Food, LLC </h1>
          </div>
          <div class="dropdown">
            <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#collapsable-nav" aria-expanded="false">
              <span class="sr-only">Toggle navigation</span>
              <span class="icon-bar"></span>
              <span class="icon-bar"></span>
              <span class="icon-bar"></span>
            </button>
            <ul class="dropdown-menu hidden-sm hidden-lg hidden-md" role="menu" aria-labelledby="menu1" id="collapsable-nav">
              <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Chicken</a></li>
              <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Beef</a></li>
              <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Sushi</a></li>
            </ul>
          </div>
        </div>
      </div>
      </div>
    </nav>
  </header>
<div id="heading" class="container text-center">
  <h2> Our Menu </h2>
</div>
<div id ="menu-sections" class="container">
  <div class="col-xs-12 text-center">
    <section><h3> Chicken </h3>
      <p>Lorem Ipsum is simply dummy text of the printing and typesetting   industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p></section></div>
  <div class="col-xs-12 text-center">
    <section><h3> Beef </h3>
      <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p></section>
  </div>
  <div class="col-xs-12 text-center">
    <section><h3> Sushi </h3>
      <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p></section>
  </div>
  </body>

我正在使用Bootstrap框架并在页面中创建了一个菜单按钮，当浏览器宽度减小时可以看到该按钮。问题是，当我按下该按钮时，会出现一个下拉菜单，标题（我们的菜单）隐藏在它后面。我想要做的是标题（我们的菜单），当我打开下拉菜单时，它下面的内容应该向下移动，当我关闭下拉菜单时，向下移动到原始位置。我该如何做到这一点？另外，如何更改菜单的背景颜色？我尝试了这个但是没有用：

.navbar-nav > li > .dropdown-menu {
  background-color: #e7e7e7;
}

Answer 1

您只需要将课程 .dropdown-menu 的位置从absolute更改为relative

.dropdown-menu {
    position: relative;
}

如果您不希望导航栏在显示下拉菜单时垂直展开，那么您应该将margin-top: 0px;添加到同一个班级

.dropdown-menu {
    position: relative;
    margin-top: 0px;
}

标题隐藏在下拉菜单

1 个答案: