渐变
线性渐变
语法：background: linear-gradient(direction, color-stop1, color-stop2, …);
从上到下
#grad1 {
height: 200px;
background: -webkit-linear-gradient(#000, #888); /* Safari 5.1 - 6.0 */
background: -o-linear-gradient(#000, #888); /* Opera 11.1 - 12.0 */
background: -moz-linear-gradient(#000, #888); /* Firefox 3.6 - 15 */
background: linear-gradient(#000, #888); /* 标准的语法（必须放在最后） */
}
从左到右
#grad2 {
height: 200px;
background: -webkit-linear-gradient(left, red , blue); /* Safari 5.1 - 6.0 */
background: -o-linear-gradient(right, red, blue); /* Opera 11.1 - 12.0 */
background: -moz-linear-gradient(right, red, blue); /* Firefox 3.6 - 15 */
background: linear-gradient(to right, red , blue); /* 标准的语法（必须放在最后） */
}
从左上到右下
#grad3 {
height: 200px;
background: -webkit-linear-gradient(left top, #000 , #888); /* Safari 5.1 - 6.0 */
background: -o-linear-gradient(bottom right, #000, #888); /* Opera 11.1 - 12.0 */
background: -moz-linear-gradient(bottom right, #000, #888); /* Firefox 3.6 - 15 */
background: linear-gradient(to bottom right, #000 , #888); /* 标准的语法（必须放在最后） */
} ---
径向渐变
语法: background: radial-gradient(center, shape size, start-color, …, last-color);
#grad6 {
height: 150px;
width: 200px;
background: -webkit-radial-gradient(red, green, blue); /* Safari 5.1 - 6.0 */
background: -o-radial-gradient(red, green, blue); /* Opera 11.6 - 12.0 */
background: -moz-radial-gradient(red, green, blue); /* Firefox 3.6 - 15 */
background: radial-gradient(red, green, blue); /* 标准的语法（必须放在最后） */
}
不均匀分布
#grad7 {
height: 150px;
width: 200px;
background: -webkit-radial-gradient(red 5%, green 15%, blue 60%); /* Safari 5.1 - 6.0 */
background: -o-radial-gradient(red 5%, green 15%, blue 60%); /* Opera 11.6 - 12.0 */
background: -moz-radial-gradient(red 5%, green 15%, blue 60%); /* Firefox 3.6 - 15 */
background: radial-gradient(red 5%, green 15%, blue 60%); /* 标准的语法（必须放在最后） */
}
椭圆形 默认
#grad8 {
height: 150px;
width: 200px;
background: -webkit-radial-gradient(red, yellow, green); /* Safari 5.1 - 6.0 */
background: -o-radial-gradient(red, yellow, green); /* Opera 11.6 - 12.0 */
background: -moz-radial-gradient(red, yellow, green); /* Firefox 3.6 - 15 */
background: radial-gradient(red, yellow, green); /* 标准的语法（必须放在最后） */
}
圆形
#grad9 {
height: 150px;
width: 200px;
background: -webkit-radial-gradient(circle, red, yellow, green); /* Safari 5.1 - 6.0 */
background: -o-radial-gradient(circle, red, yellow, green); /* Opera 11.6 - 12.0 */
background: -moz-radial-gradient(circle, red, yellow, green); /* Firefox 3.6 - 15 */
background: radial-gradient(circle, red, yellow, green); /* 标准的语法（必须放在最后） */
}
重复
#grad10 {
height: 150px;
width: 200px;
background: -moz-repeating-radial-gradient(#ace, #ace 5px, #f96 5px, #f96 10px);
background: -webkit-repeating-radial-gradient(#ace, #ace 5px, #f96 5px, #f96 10px);
background: -moz-repeating-linear-gradient(top left -45deg, #ace, #ace 5px, #f96 5px, #f96 10px);
background: -webkit-repeating-linear-gradient(top left -45deg, #ace, #ace 5px, #f96 5px, #f96 10px);
}
demo
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>渐变</title>
<style>
/*从上到下*/
#grad1 {
height: 200px;
background: -webkit-linear-gradient(#000, #888); /* Safari 5.1 - 6.0 */
background: -o-linear-gradient(#000, #888); /* Opera 11.1 - 12.0 */
background: -moz-linear-gradient(#000, #888); /* Firefox 3.6 - 15 */
background: linear-gradient(#000, #888); /* 标准的语法（必须放在最后） */
}
/*从左到右*/
#grad2 {
height: 200px;
background: -webkit-linear-gradient(left, red , blue); /* Safari 5.1 - 6.0 */
background: -o-linear-gradient(right, red, blue); /* Opera 11.1 - 12.0 */
background: -moz-linear-gradient(right, red, blue); /* Firefox 3.6 - 15 */
background: linear-gradient(to right, red , blue); /* 标准的语法（必须放在最后） */
}
/*从左上到右下*/
#grad3 {
height: 200px;
background: -webkit-linear-gradient(left top, #000 , #888); /* Safari 5.1 - 6.0 */
background: -o-linear-gradient(bottom right, #000, #888); /* Opera 11.1 - 12.0 */
background: -moz-linear-gradient(bottom right, #000, #888); /* Firefox 3.6 - 15 */
background: linear-gradient(to bottom right, #000 , #888); /* 标准的语法（必须放在最后） */
}
/*彩虹渐变*/
#grad4 {
height: 55px;
background: -webkit-linear-gradient(left, red, orange, yellow, green, blue, indigo, violet); /* Safari 5.1 - 6.0 */
background: -o-linear-gradient(left, red, orange, yellow, green, blue, indigo, violet); /* Opera 11.1 - 12.0 */
background: -moz-linear-gradient(left, red, orange, yellow, green, blue, indigo, violet); /* Firefox 3.6 - 15 */
background: linear-gradient(to right, red, orange, yellow, green, blue, indigo, violet); /* 标准的语法（必须放在最后） */
}
#grad5 {
height: 200px;
background: -webkit-linear-gradient(left, rgba(255,0,0,0), rgba(255,0,0,1)); /* Safari 5.1 - 6.0 */
background: -o-linear-gradient(right, rgba(255,0,0,0), rgba(255,0,0,1)); /* Opera 11.1 - 12.0 */
background: -moz-linear-gradient(right, rgba(255,0,0,0), rgba(255,0,0,1)); /* Firefox 3.6 - 15 */
background: linear-gradient(to right, rgba(255,0,0,0), rgba(255,0,0,1)); /* 标准的语法（必须放在最后） */
}
/*径向渐变*/
/*均匀分布*/
#grad6 {
height: 150px;
width: 200px;
background: -webkit-radial-gradient(red, green, blue); /* Safari 5.1 - 6.0 */
background: -o-radial-gradient(red, green, blue); /* Opera 11.6 - 12.0 */
background: -moz-radial-gradient(red, green, blue); /* Firefox 3.6 - 15 */
background: radial-gradient(red, green, blue); /* 标准的语法（必须放在最后） */
}
/*不均匀分布*/
#grad7 {
height: 150px;
width: 200px;
background: -webkit-radial-gradient(red 5%, green 15%, blue 60%); /* Safari 5.1 - 6.0 */
background: -o-radial-gradient(red 5%, green 15%, blue 60%); /* Opera 11.6 - 12.0 */
background: -moz-radial-gradient(red 5%, green 15%, blue 60%); /* Firefox 3.6 - 15 */
background: radial-gradient(red 5%, green 15%, blue 60%); /* 标准的语法（必须放在最后） */
}
/*椭圆形 默认*/
#grad8 {
height: 150px;
width: 200px;
background: -webkit-radial-gradient(red, yellow, green); /* Safari 5.1 - 6.0 */
background: -o-radial-gradient(red, yellow, green); /* Opera 11.6 - 12.0 */
background: -moz-radial-gradient(red, yellow, green); /* Firefox 3.6 - 15 */
background: radial-gradient(red, yellow, green); /* 标准的语法（必须放在最后） */
}
/*圆形*/
#grad9 {
height: 150px;
width: 200px;
background: -webkit-radial-gradient(circle, red, yellow, green); /* Safari 5.1 - 6.0 */
background: -o-radial-gradient(circle, red, yellow, green); /* Opera 11.6 - 12.0 */
background: -moz-radial-gradient(circle, red, yellow, green); /* Firefox 3.6 - 15 */
background: radial-gradient(circle, red, yellow, green); /* 标准的语法（必须放在最后） */
}
/*重复*/
#grad10 {
height: 150px;
width: 200px;
background: -moz-repeating-radial-gradient(#ace, #ace 5px, #f96 5px, #f96 10px);
background: -webkit-repeating-radial-gradient(#ace, #ace 5px, #f96 5px, #f96 10px);
background: -moz-repeating-linear-gradient(top left -45deg, #ace, #ace 5px, #f96 5px, #f96 10px);
background: -webkit-repeating-linear-gradient(top left -45deg, #ace, #ace 5px, #f96 5px, #f96 10px);
}
.flex-box{
display: flex;
}
.flex-item{
margin-left: 30px;
}
</style>
</head>
<body>
<h3>线性渐变 - 从上到右</h3>
<div id="grad1"></div>
<h3>线性渐变 - 从左到右</h3>
<div id="grad2"></div>
<h3>线性渐变 - 从左上到右下</h3>
<div id="grad3"></div>
<h3>彩虹渐变</h3>
<div id="grad4" style="text-align:center;margin:auto;color:#999;font-size:40px;font-weight:bold">渐变背景</div>
<h3>线性渐变 - 透明度</h3>
<p>为了添加透明度，我们使用 rgba() 函数来定义颜色结点。rgba() 函数中的最后一个参数可以是从 0 到 1 的值，它定义了颜色的透明度：0 表示完全透明，1 表示完全不透明。</p>
<div id="grad5"></div>
<h1 style="text-align:center;margin:auto;color:#333;font-weight:bold">径向渐变</h1>
<div class="flex-box">
<div class="flex-item">
<h3>径向渐变 - 颜色结点均匀分布</h3>
<div id="grad6"></div>
</div>
<div class="flex-item">
<h3>径向渐变 - 颜色结点不均匀分布</h3>
<div id="grad7"></div>
</div>
<div class="flex-item">
<p><strong>椭圆形 Ellipse（默认）：</strong></p>
<div id="grad8"></div>
</div>
<div class="flex-item">
<p><strong>圆形 Circle：</strong></p>
<div id="grad9"></div>
</div>
<div class="flex-item">
<p><strong>重复：</strong></p>
<div id="grad10"></div>
</div>
</div>
<p><strong>注意：</strong> Internet Explorer 9 及之前的版本不支持渐变。</p>
</body>
</html>
