<nav>
	<ul>
	<li>哈哈哈</li>
	<li>吼吼吼</li>
	<li>嘿嘿嘿</li>
	<li>嘎嘎嘎</li>
	<li class="move"></li>
	<!--<li class="fly fly1"></li>
	<li class="fly fly2"></li>
	<li class="fly fly3"></li>
	<li class="fly fly4"></li>
	-->
	</ul>
	</nav>

nav,
ul,
li {
	padding: 0;
	margin: 0;}
nav {
	position: relative;
	left: 35%;
	top: 20px;
	
	width: 30%;
	height: 60px;
	background-color: #66CCFF;
	
	box-sizing: border-box;
	display: inline-block;
	}
ul {
	width: 100%;
	height: 60px;
	vertical-align: middle;
	}
li {
	display: inline-block;
	
	width: 20%;
	text-align: center;
	height: 60px;
	line-height: 60px;
	cursor: pointer;
	color: #000000;
	
	transition: color 0.4s ease-in-out;
	}
li:hover {
	color: #FFFFFF;}
.move {
	display: inline-block;
	border: 4px solid #FF3333;
	height: 0px;
	background-color: #FF3333;
	
	position: absolute;
	left: 0;
	top: 56px;
	
	transition: left 0.4s ease-in-out;}
li:nth-child(1):hover~.move {
	left: 0;}
li:nth-child(2):hover~.move {
	left: 20%;}
li:nth-child(3):hover~.move {
	left: 40%;}
li:nth-child(4):hover~.move {
	left: 60%;}