【发布时间】：2018-11-12 14:47:55
【问题描述】：
尝试使用 Bootstrap 创建一个简单的选项卡式站点，我希望顶部的导航栏有一个背景图像。但是，背景图像永远不会出现。这不太可能是路径问题，因为 (a) IDE (IntelliJ IDEA) 在项目中正确找到了相对路径，并且 (b) 使用 http://... 的图像 URL 也不起作用。似乎 background-image 属性永远不会被识别。
这是我目前所拥有的：
.navbar > .container .navbar-brand, .navbar > .container-fluid .navbar-brand {
margin-left: -8px;
height: 46px; <!-- navbar-height -->
}
.navbar-custom {
background: rgba(52, 73, 94, 0.7); <!-- navbar-bgcolor -->
background-image: url("https://jessicasse.files.wordpress.com/2012/10/distant-lights-1-1152x8641.jpg");
position: absolute;
top: 0;
left: 0;
width: 100%;
z-index: 3;
font-family: 'Lato', 'Open Sans', 'Helvetica Neue', Helvetica, Calibri, Arial, sans-serif; <!-- heading font -->
}
.navbar-custom .navbar-brand {
font-size: inherit;
font-weight: lighter;
font-kerning: auto;
font-family: 'Lato', 'Open Sans', 'Helvetica Neue', Helvetica, Calibri, Arial, sans-serif; <!-- heading font -->
}
.navbar-custom .nav li a {
font-size: 14px;
font-weight: lighter;
letter-spacing: 1px;
}
.navbar-default .navbar-nav > .current > a,
.navbar-default .navbar-nav > .current > a:hover,
.navbar-default .navbar-nav > .current > a:focus {
font-weight: bolder;
}
.navbar-default .navbar-nav > li > a {
color: ghostwhite;
}<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="x-ua-compatible" content="ie=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="description" content="My Home Page">
<title>My Home Page</title>
<link rel="stylesheet" type="text/css" href="assets/css/bootstrap.css">
<link rel="stylesheet" type="text/css" href="assets/css/bootstrap-theme.css">
<link rel="stylesheet" type="text/css" href="assets/css/font-awesome.css">
<link rel="stylesheet" type="text/css" href="assets/css/main.css">
<!-- Custom Fonts -->
<link rel="stylesheet" type="text/css" href="assets/fonts/Lato:300,400,700,300italic,400italic.css">
<link rel="stylesheet" type="text/css" href="assets/fonts/Lora:400,700,400italic,700italic.css">
</head>
<body>
<nav class="navbar navbar-default navbar-custom navbar-fixed-top">
<div class="container-fluid">
<!-- Brand and toggle get grouped for better mobile display -->
<div class="navbar-header page-scroll">
<div>
<a style="color: ghostwhite; font-size: xx-large; font-weight: lighter" href="">This Page</a>
<br>
<p>
<span style="color: ghostwhite; font-size: medium; font-weight: lighter">Job Title</span><br>
<span style="color: ghostwhite; font-size: medium; font-weight: lighter">Company</span>
</p>
</div>
</div>
<!-- Collect the nav links, forms, and other content for toggling -->
<div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
<ul class="nav navbar-nav navbar-right">
<li class="current"><a href="#">Home</a></li>
<li><a href="research.html">Research</a></li>
<li><a href="teaching.html">Teaching</a></li>
</ul>
</div>
<!-- /.navbar-collapse -->
</div>
<!-- /.container -->
</nav>
</body>
</html>我明白（如果我弄错了，请纠正我）main.css 应该覆盖bootstrap.css 中的规范。但是，如果我从main.css 中删除background: rgba(52, 73, 94, 0.7); 行，则结果只是boostrap.css 中指定的默认值（如果此处相关，则为Bootstrap v3.3.4）。
【问题讨论】：
标签： html css twitter-bootstrap background-image background-color