一、理论：
1.CSS3颜色模式
a.RGBA颜色模式，在RGB基础上加了控制alpha透明度的参数
b.HSL颜色模式：色调 饱和度 亮度
c.HSLA颜色模式：A值取于0-1之间，值越大，透明度越低
2.RGBA/HSLA滤镜格式
a.需要用转换工具才能在ie8及以下版本中使用RGBA/HSLA颜色模式相同的透明度，需要将RGBA/HSLA中的透明值乘以255，然后将其转换成十六进制值
二、实践：
1.
<meta charset="UTF-8"> <title>Title</title> <style type="text/css"> .row{ overflow: hidden; } .row div{ width: 80px; height: 80px; line-height: 80px; text-align: center; float:left; } .row:nth-of-type(1) div { background: rgba(135,162,31,0.8); } .row:nth-of-type(2) div { background: rgba(135,162,31,0.6); } .row:nth-of-type(3) div { background: rgba(135,162,31,0.4); } .row:nth-of-type(4) div{ background: rgba(135,162,31,0.2); } .row div:nth-child(1){ background: rgba(135,162,31,0.8); } .row div:nth-child(2){ background: rgba(135,162,31,0.7); } .row div:nth-child(3){ background: rgba(135,162,31,0.6); } .row div:nth-child(4){ background: rgba(135,162,31,0.5); } .row div:nth-child(5){ background: rgba(135,162,31,0.4); } .row div:nth-child(6){ background: rgba(135,162,31,0.3); } .row div:nth-of-type(1) div { background: rgba(135,162,31,0.2); } </style><div class="demo"> <div class="row"> <div> 1 </div> <div> 0.8 </div> <div> 0.6 </div> <div> 0.4 </div> <div> 0.2 </div> </div> <div class="row"> <div> 1 </div> <div> 0.8 </div> <div> 0.6 </div> <div> 0.4 </div> <div> 0.2 </div> </div> <div class="row"> <div> 1 </div> <div> 0.8 </div> <div> 0.6 </div> <div> 0.4 </div> <div> 0.2 </div> </div> <div class="row"> <div> 1 </div> <div> 0.8 </div> <div> 0.6 </div> <div> 0.4 </div> <div> 0.2 </div> </div> <div class="row"> <div> 1 </div> <div> 0.8 </div> <div> 0.6 </div> <div> 0.4 </div> <div> 0.2 </div> </div>
</div> <meta charset="UTF-8"> <title>Title</title> <style type="text/css"> .row{ overflow: hidden; } .row div{ width: 80px; height: 80px; line-height: 80px; text-align: center; float:left; } .row:nth-of-type(1) div { background: hsl(133,100%,80%); } .row:nth-of-type(2) div { background: hsl(133,80%,80%); } .row:nth-of-type(3) div { background: hsl(133,60%,80%); } .row:nth-of-type(4) div{ background: hsl(133,50%,80%); } .row div:nth-child(1){ background: hsl(33,100%,70%); } .row div:nth-child(2){ background: hsl(33,90%,70%); } .row div:nth-child(3){ background: hsl(33,80%,70%); } .row div:nth-child(4){ background: hsl(33,70%,70%); } .row div:nth-child(5){ background: hsl(33,60%,70%); } .row div:nth-child(6){ background: hsl(33,50%,70%); } .row div:nth-of-type(1) div { background: hsl(33,100%,70%); } </style><div class="demo"> <div class="row"> <div> 1 </div> <div> 0.8 </div> <div> 0.6 </div> <div> 0.4 </div> <div> 0.2 </div> </div> <div class="row"> <div> 1 </div> <div> 0.8 </div> <div> 0.6 </div> <div> 0.4 </div> <div> 0.2 </div> </div> <div class="row"> <div> 1 </div> <div> 0.8 </div> <div> 0.6 </div> <div> 0.4 </div> <div> 0.2 </div> </div> <div class="row"> <div> 1 </div> <div> 0.8 </div> <div> 0.6 </div> <div> 0.4 </div> <div> 0.2 </div> </div> <div class="row"> <div> 1 </div> <div> 0.8 </div> <div> 0.6 </div> <div> 0.4 </div> <div> 0.2 </div> </div>
</div>
