CSS伪元素 特效

你所不知的 CSS ::before 和 ::after 伪元素用法

（1）鼠标移上链接，出现方括号

a {
	position: relative;
	display: inline-block;
	outline: none;
	text-decoration: none;
	color: #000;
	font-size: 32px;
	padding: 5px 10px;
}

a:hover::before, a:hover::after { position: absolute; }
a:hover::before { content: "\5B"; left: -20px; }
a:hover::after { content: "\5D"; right:  -20px; }

（2）悬浮出现双边框

  

a {
	position: relative;
	display: inline-block;
	outline: none;
	text-decoration: none;
	color: #000;
	font-size: 32px;
	padding: 0 10px;
}

/* 大框 */
a:hover::before, a:hover::after { 
	content: "";
	display: block;
	position: absolute;
	top: -15%%;
	left: -14%%;
	width: 120%;
	height: 120%;
	border-style: solid;
	border-width: 4px;
	border-color: #DDD;
 }

/* 小框 */
 a:hover::after {
 	top: 0%;
 	left: 0%;
	width: 100%;
	height: 100%;
	border-width: 2px;
 }