css

去除元素最外层的边线

outline: none;

实现背景移动

-webkit-animation: animate-cloud 20s linear infinite;

animation: animate-cloud 20s linear infinite;

图标墙

background-position: 10px -53px !important;

background: #eae7e7 url(../../Image/8bcLQqF.png) no-repeat;

before and after

<style type="text/css">
#example:before {
content: "‘我是before’";
color: red;
}

#example:after {
content: "‘我是after’";
color:blue;
}
</style>
<p id="example">before and after</p>
</div>

:target实现元素的切换

<style type="text/css">
#btn{
80px;
height:40px;
border:0px;
background-color: red;
border-radius:5px;
outline: none;
}
#btn:target{
background-color:blue;
}
</style>
<div id="ttttt">
<a id="aaaaa" href="#btn">1231231231231</a>

<button id="btn">提交</button>

高度控制

rem vh vw vmin vmax ex ch  height:calc(100vh-30px);