JavaScript获取伪类元素进行修改

// An highlighted block
let verification = document.querySelector('.verification');
let width = window.getComputedStyle(verification, "after").getPropertyValue('width');
/** 改变伪类 **/
function css(style_text) {
var s = document.createElement('style');
s.innerText = style_text;
document.head.appendChild(s);
}
css('.verificati::after{display:block}');