css3的gradient分为两种：线性渐变（linear）和径向渐变（radial）。
一、线性渐变linear-gradient
1、介绍
linear-gradient([设置方向]，[设置开始颜色]，[设置多种过度颜色]，[设置结束颜色])
参数：
第一个参数：指定渐变方向，可以用“角度”的关键字或“英文”来表示：
第一个参数默认：180deg，等同于“to bottom”。
后面的颜色至少有2个，即开始颜色和结束颜色。
2、使用
a、举例：
<style type="text/css">
p{
width: 300px;
height: 100px;
background-image:linear-gradient(to right, red, orange, yellow, green, blue, indigo, violet);
}
</style>
<p>从左到右线性渐变背景</p>
b、一个非常酷的功能：用渐变制作导航分割线
background:linear-gradient(to bottom,#dd2926,#a82724,#dd2926) no-repeat right / 1px 15px; 意思背景使用渐变色，然后不重复，居右，斜线后面的其实是background-size的设置，width 1px，height 15px
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>CSS制作立体导航</title>
<link rel="stylesheet" href="http://www.w3cplus.com/demo/css3/base.css" rel="external nofollow" >
<style>
body{
background: #ebebeb;
}
.nav{
width:560px;
height: 50px;
font:bold 0/50px Arial;
text-align:center;
margin:40px auto 0;
background: #f65f57;
/*制作圆*/
border-radius:10px;
/*制作导航立体风格*/
box-shadow:0 5px rgb(176,72,63);
}
.nav a{
display: inline-block;
-webkit-transition: all 0.2s ease-in;
-moz-transition: all 0.2s ease-in;
-o-transition: all 0.2s ease-in;
-ms-transition: all 0.2s ease-in;
transition: all 0.2s ease-in;
}
.nav a:hover{
-webkit-transform:rotate(10deg);
-moz-transform:rotate(10deg);
-o-transform:rotate(10deg);
-ms-transform:rotate(10deg);
transform:rotate(10deg);
}
.nav li{
position:relative;
display:inline-block;
padding:0 16px;
font-size: 13px;
text-shadow:1px 2px 4px rgba(0,0,0,.5);
list-style: none outside none;
/*制作导航分隔线*/
background:linear-gradient(to bottom,#dd2926,#a82724,#dd2926) no-repeat right / 1px 15px;
}
/*使用伪元素制作导航列表项分隔线*/
/*删除第一项和最后一项导航分隔线*/
.nav li:last-child{
background: none;
} .nav a,
.nav a:hover{
color:#fff;
text-decoration: none;
} </style>
</head>
<body>
<ul class="nav">
<li>
<a href="" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Home</a>
</li>
<li>
<a href="" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >About Me</a>
</li>
<li>
<a href="" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Portfolio</a>
</li>
<li>
<a href="" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Blog</a>
</li>
<li>
<a href="" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Resources</a>
</li>
<li>
<a href="" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Contact Me</a>
</li>
</ul>
</body>
</html>
效果：
c、谷歌搜索低调的线性渐变背景
查看了一个google搜索的代码，写了个例子
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>starof test demo</title>
<style type="text/css">
input[type="submit"]{
height: 29px;
line-height: 27px;
}
input[type="submit"]{
background-image: -webkit-gradient(linear,left top,left bottom,from(#f5f5f5),to(#f1f1f1));
background-image: -webkit-linear-gradient(top,#f5f5f5,#f1f1f1);
background-image: -o-linear-gradient(top,#f5f5f5,#f1f1f1);
background-image: linear-gradient(top,#f5f5f5,#f1f1f1);
background-color: #f5f5f5;
border: 1px solid #dcdcdc;
border: 1px solid rgba(0,0,0,0.1);
-webkit-border-radius: 2px;
border-radius: 2px;
color: #444;
/*以上*/
-webkit-user-select: none;
cursor: default;
font-family: arial,sans-serif;
font-size: 11px;
font-weight: bold;
margin: 11px 8px;
min-width: 54px;
padding: 0 8px;
text-align: center;
}
input[type="submit"]:hover{
background-image: -webkit-gradient(linear,left top,left bottom,from(#f8f8f8),to(#f1f1f1));
background-image: -webkit-linear-gradient(top,#f8f8f8,#f1f1f1);
background-image: -o-linear-gradient(top,#f8f8f8,#f1f1f1);
background-image: linear-gradient(top,#f8f8f8,#f1f1f1);
background-color: #f8f8f8;
border: 1px solid #c6c6c6;
-webkit-box-shadow: 0 1px 1px rgba(0,0,0,0.1);
box-shadow: 0 1px 1px rgba(0,0,0,0.1);
color: #222;
}
</style>
</head>
<body>
<input value="Google 搜索" name="btnK" type="submit"/>
<input value=" 手气不错 " name="btnI" type="submit">
</body>
</html>
二、径向渐变radial-gradient
待续
大漠写的css3 gradient
http://www.w3cplus.com/content/css3-gradient
