js 操作伪元素样式

获取：

var odiv=document.getElementById("show");

var content = window.getComputedStyle(document.querySelector('.element'),':before')

.getPropertyValue('content’)

https://www.cnblogs.com/tugenhua0707/p/10004654.html

• <style>.sheet.cssRules[0].style
• <link>.sheet.insertRule