原文：https://blog.csdn.net/insgo/article/details/113799700

// ==UserScript==
// @name         totop
// @namespace    http://unamerrr.net/
// @version      0.1
// @match        *://*/*
// @description  返回顶部
// @author       unamerrr
// @grant        none
// ==/UserScript==
(function() {
    'use strict';
    var toTopBtn = document.createElement('button') toTopBtn.innerHTML = "返回顶部"toTopBtn.className = "a-b-c-d-toTop"toTopBtn.onclick = function(e) {
        scrollTo(0, 0)
    }
    var body = document.body
    var style = document.createElement('style') style.id = "a-b-c-d-style"
    var css = `.a - b - c - d - toTop {
        position: fixed;
        bottom: 10 % ;
        right: 5 % ;
        width: 50px;
        height: 50px;
        border - radius: 50 % ;
        font - size: 15px;
        z - index: 999;
        cursor: pointer;
        font - size: 12px;
        overflow: hidden;
    }`
    if (style.styleSheet) {
        style.styleSheet.cssText = css;
    } else {
        style.appendChild(document.createTextNode(css));
    }
    body.appendChild(toTopBtn) body.appendChild(style)
    // Your code here...
})();