代码结构

1. HTML代码

<style type="text/css">
.menu-list{list-style:none; width:300px; margin: 100px auto;}
.menu-list li{display:block;}
.list{list-style: none; margin-left: -50px;  width:300px; height:60px; overflow:hidden; }
.list li{width: 300px;height: 60px; position: relative; animation: myfirst 4s infinite ;line-height: 60px;text-align: center; font-size: 30px;color:#fff;}
@keyframes myfirst
{
	0%    {background-color:#4ec7f3;  top:0px;}
	25%   {background-color:#4ec7f3;  top:0px;}
	50%  {background:#42c58a; top:-60px;}
	75%  {background:#a0a0a0; top:-120px;}
	100%  {background:#dc143c; top:-180px;}
}           
.font30{
	font-size: 30px;
	color: #7d7d7d;
}
</style>
<ul class="menu-list">
	<li><p class="font30">今天怎么样<b id="b1">?</b></p></li>
	<li>
		<ul class="list">
		<li class="one">还行</li>
		<li class="two">该充电</li>
		<li class="three">学习一下</li>
		<li class="four">我想一想</li>
	</ul>
</li>
<li><p class="font30">要充电了</p></li>
</ul>