kemono.su navbar duplicator

Add another navbar to post end

// ==UserScript==
// @name          kemono.su navbar duplicator
// @namespace       http://tampermonkey.net/
// @version        1.0
// @description     Add another navbar to post end
// @match         https://kemono.su/*
// @author         rainbowflesh
// @grant         none
// @license MIT
// ==/UserScript==

(function () {
    'use strict';

    let isNavCloned = false;

    function insertAfter(newNode, referenceNode) {
        referenceNode.parentNode.insertBefore(newNode, referenceNode.nextSibling);
    }

    function tryCloneAndInsert() {
        if (isNavCloned) return;

        const nav = document.querySelector("nav.post__nav-links");
        const body = document.querySelector("div.post__body");

        if (nav && body) {
            const clone = nav.cloneNode(true);
            insertAfter(clone, body);
            isNavCloned = true;
        }
    }

    const observer = new MutationObserver((mutationsList) => {
        // Look for the specific target nodes that are added to the DOM
        for (let mutation of mutationsList) {
            if (mutation.type === 'childList') {
                tryCloneAndInsert();
            }
        }
    });

    observer.observe(document.body, { childList: true, subtree: true });

    window.addEventListener('load', tryCloneAndInsert);
})();