【发布时间】：2015-06-19 09:38:42
【问题描述】：
我很好奇当您向下滚动到页面上的某个点或 DIV 时，如何让粘性导航栏淡出颜色。
我想要这个，这样当我滚动到 div 的末尾或 div 的开头时，我可以看到白色背景上的白色。
我的一个问题是无法让 JS 工作以及将我的背景图片插入到我的 css 中...标题 {} 宽度...我如何仅定位徽标（在左边）和右边的导航栏......所以一个透明栏出现在两者下方，占据页面所需的高度和 100% 的宽度，而不会弄乱背景图像！
同样在 codepen 中，您会注意到更改颜色的标题...位于主 div 下方。
这是我的代码笔...
http://codepen.io/uchmanowicz/pen/qEebbN
谢谢！
HTML
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Aesthetic Media</title>
<link href="styles.css" rel="stylesheet" type="text/css"/>
<link href='http://fonts.googleapis.com/css?family=Raleway:400,700,500' rel='stylesheet' type='text/css'>
<script type="text/javascript" src="styles.js"></script>
</head>
<body>
<header>
<a class="logo" href="#">Aesthetic</a>
<nav>
<li><a href="#">Home</a></li>
<li><a href="#">About</a></li>
<li><a href="#">Gallery</a></li>
<li><a href="#">Contact</a></li>
</nav
<div class="clears"></div>
<div class="maintext">
<h1>We're Aesthetic</h1>
<h2>A Visual Agency from Niagara</h2>
</div>
</header>
<main>
<h2 class="whatwedo">Expertise</h2>
<div class="whatwedobox one"><div class="icon"></div><p>Lorem ipsum dolor sit amet.</p></div>
<div class="whatwedobox two"></div>
<div class="whatwedobox three"></div>
</main>
<footer></footer>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js"> </script>
</body>
</html>
CSS
* {
box-sizing: border-box;
margin: 0px;
padding: 0px;
}
body {
background: white;
}
header {
width: 100%;
height: 550px;
background: white;
background: url('images/main.jpg') center center;
background-size: cover;
padding: 30px 30px 30px 30px;
position: relative;
}
.logo {
position: fixed;
top: 33px;
left: 30px;
width: 200px;
height: 80px;
display: block;
float: left;
z-index: 30;
font-size: 1.8em;
font-weight: 800;
text-decoration: none;
color: #FFFFFF;
font-family: 'Raleway' , sans-serif, Helvetica, Verdana;
text-transform: uppercase;
font-weight: bold;
letter-spacing: 5px;
}
.logo a {
font-size: 1.8em;
font-weight: 800;
text-decoration: none;
color: #FFFFFF;
font-family: 'Raleway' , sans-serif, Helvetica, Verdana;
text-transform: uppercase;
font-weight: bold;
letter-spacing: 5px;
}
nav {
float: right;
z-index: 30;
position: fixed;
top: 20px;
right: 0px;
letter-spacing: .2em;
}
nav li {
float: left;
list-style: none;
padding: 10px 15px 10px 15px;
}
nav li:last-child {
border-right: none;
}
nav li a {
padding: 5px 10px 5px 10px;
color: white;
display: block;
font-weight: 400;
text-decoration: none;
color: #FFFFFF;
font-family: 'Raleway' , sans-serif, Helvetica, Verdana;
text-transform: uppercase;
-webkit-font-smoothing: antialiased;
}
nav li a:hover {
background-color: rgba(40, 40, 40, 0.5);
-moz-transition: all .3s ease;
-o-transition: all .3s ease;
-ms-transition: all .3s ease;
-transition: all .3s ease;
-webkit-transition: all .3s ease;
-webkit-font-smoothing: antialiased;
}
.clears {
clear: both;
}
.maintext {
margin: auto;
width: 600px;
text-align: center;
margin-top: 200px;
color: white;
z-index: 30;
position: relative;
}
.maintext h1 {
font-weight: 600;
font-size: 1.8em;
line-height: 1.2em;
text-transform: uppercase;
letter-spacing: .1em;
color: #FFFFFF;
font-family: 'Raleway' , sans-serif, Helvetica, Verdana;
padding-bottom: 15px;
}
.maintext h2 {
font-weight: 400;
font-size: 1.7em;
line-height: 1.2em;
text-transform: uppercase;
letter-spacing: .1em;
text-align: center;
color: #FFFFFF;
font-family: 'Raleway' , sans-serif, Helvetica, Verdana;
padding-bottom: 15px;
}
main {
max-width: 1180px;
margin: auto;
margin-top: 20px;
overflow: hidden;
}
h2.whatwedo {
text-align: center;
font-weight: 400;
font-size: 1.7em;
line-height: 1.2em;
text-transform: uppercase;
letter-spacing: .1em;
color: #000000;
font-family: 'Raleway' , sans-serif, Helvetica, Verdana;
-webkit-font-smoothing: antialiased;
}
.whatwedobox {
width: 30%;
height: 300px;
border: 1px solid blue;
float: left;
margin-right: 5%;
padding: 20px;
margin-top: 20px;
}
.whatwedobox:last-child {
margin-right: 0%;
}
.icon {
width: 100%;
height: 100px;
background: url(#) no-repeat center center;
}
JS
$(document).ready(function(){
var scroll_start = 0;
var startchange = $(".maintext");
var offset = startchange.offset();
if (startchange.length){
$(document).scroll(function() {
scroll_start = $(this).scrollTop();
if(scroll_start > offset.top) {
$("header").css('background-color', '#B5B5B5');
} else {
$('header').css('background-color', 'transparent');
}
});
}
});
【问题讨论】：
标签： javascript html css