伪元素after,before，css/js控制样式

CSS
<style>
    body {
        font: 200%/1.45 charter;
    }
    ref::before {
        content: '0A7';
        letter-spacing: .1em;
    }
</style>
JS
并不能获取到元素因为是伪的假的元素
得还去改变style
document.styleSheets[0].addRule('.red::before','color: green');

http://pankajparashar.com/posts/modify-pseudo-elements-css/