tab切换html和css

	<style>
	.p {
		font-size: 0;
	}
		.s {
			position: relative;
			width: 50px;
			line-height: 50px;
			text-align: center;
			border:1px solid #ddd;
			box-sizing: border-box;
			display: inline-block;
			font-size: 14px;
		}
		.s+.s {
			margin-left: -1px;
		}
    .s.active {
     border-color: red;
     color: red;
     z-index: 9;
    }
	</style>

<div class="p">
		<div class="s ">1</div>
		<div class="s active">2</div>
		<div class="s">3</div>
		<div class="s">4</div>
	</div>