CSS--使用伪选择器制作箭头图标

HTML

<section class="main">
<header class="title">图标变形过渡效果缩放式菜单</header>
<section>
<button>图标</button>
<header>
#300x100 淡色系
</header>
<div>
<article>
<img src="http://www.gbtags.com/gb/laitu/300x100" alt="" />
</article>
</div>
</section>
<section>
<button>图标</button>
<header>
#300x100 暗色系
</header>
<div>
<article>
<img src="http://www.gbtags.com/gb/laitu/300x100/666666/ffffff" alt="" />
</article>
</div>
</section>
</section>

CSS

* { box-sizing:border-box;}
body { font-family: 'microsoft yahei',Arial,sans-serif; background: #aaa;}
section { position: relative; width:100%;}
section.main { position: absolute; top:10%; left:25%;  width:50%; max-width:30em; min-width:15em; border-radius:5px; overflow: hidden;}
section.main > header { background: orange; color:#fff; line-height: 1.2em; text-align: center;}
section section:last-child { border:none;}
section > div { height:0; overflow: hidden; transition:all .4s ease-in-out;}
article,header { padding:1em; line-height: 1em;}
header:not(.title) { width:100%; overflow: hidden; height:3em; background: #efefef; cursor:pointer; color:#888; white-space:nowrap; text-overflow: ellipsis; padding-right: 2.1em;}
header:not(.title):hover { background: #e8e8e8;}
article { line-height: 1.4em; background: rgba(255, 255, 255, .7);}
article img { width:100%; height:auto; border:2px solid white; border-radius: 3px;}

/* 使用CSS3的伪选择器,生成关闭和向下两个图标按钮; */
/* 使用变形属性,组合位移和旋转,可将生成的小矩形组合成向下按钮,同样也可以组装成关闭按钮; */
section button { position: absolute; right:0; margin:0; padding:0; height:3em; width:3em; outline:none; border:0; background: none; text-indent: -9999px; pointer-events:none; cursor:pointer;}
section button:before,
section button:after { content:''; display: block; position: absolute; width:4px; height:12px; background: orange; border-radius: .3em; top:50%; left:50%; transition:all .3s ease-in-out;}

/*向左箭头*/
/*section button:before { transform:translate(0%, -50%) rotate(45deg);}
section button:after { transform:translate(0%, 0%) rotate(-45deg);}*/

/*向右箭头*/
/*section button:before { transform:translate(0%, -50%) rotate(-45deg);}
section button:after { transform:translate(0%, 0%) rotate(45deg);}*/

/*向上箭头*/
/*section button:before { transform:translate(75%, -20%) rotate(-45deg);}
section button:after { transform:translate(-75%, -20%) rotate(45deg);}*/

/*向下箭头*/
section button:before { transform:translate(75%, 0%) rotate(45deg);}
section button:after { transform:translate(-75%, 0%) rotate(-45deg);}

/* 点击之后需要变成"X"; */
section.open button:after,section.open button:before { background: red; height:14px; }
section.open button:before { transform:translate(-75%, -20%) rotate(45deg);}
section.open button:after { transform:translate(-75%, -20%) rotate(-45deg);}

JavaScript

$(function(){
$('section section header').on('click', function () {
var $this = $(this),
parent_section = $this.parent(),
closeDiv = $this.siblings('div'),
contentheight = closeDiv.children('article').outerHeight();
(closeDiv.height() === 0 ) ? closeDiv.height(contentheight) : closeDiv.height(0);
// 更改容器高度;
$this.parents('section').first().toggleClass('open');
// 更改箭头样式;
});
});