:before :after
偽元素
可以為元素添加更多的樣式
注意設(shè)置content
例子
#nav-toggle span,#nav-toggle span:before,#nav-toggle span:after{
width: 35px;height: 7px;
position: absolute;
border-radius: 2px;
display: block;
background-color: #353535;
content:''
}
#nav-toggle span:before{top:-10px}
#nav-toggle span:after{bottom: -10px}
#nav-toggle.active span{background-color: transparent}
#nav-toggle.active span:before{transform: rotate(45deg);top:0}
#nav-toggle.active span:after{transform:translateY(-10px) rotate(-45deg)}
該方法實(shí)現(xiàn)了圖標(biāo)變化
