Userscript: Remove / Toggle scrollbars for Sizzy (https://github.com/kitze/sizzy)

sizzy-no-scrollbars.js

// ==UserScript==
// @name         Toggle Sizzy Scrollbars
// @namespace    http://tampermonkey.net/
// @version      1.0
// @description  Removes scrollbars from Sizzy's iframes whilst providing a manual override button for each iframe too.
// @author       Harry Phillips
// @match        http://sizzy.co/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    var
        // configure width of scrollbar for your browser, this value is what worked
        // best with Vivaldi, which is Chrome based.
        SCROLLBAR_WIDTH = 21,

        // remove scrollbars by default?
        SCROLLBAR_OFF_DEFAULT = true,

        // selectors, these may change?
        S_WRAPPERS = ".hzEJjj",
        S_CONTROLS = ".hJSWmc",

        // class names, these may change too?
        C_BUTTON = "bUwDjg",
        C_ICON = "jFTSbQ";

    document.querySelectorAll(S_WRAPPERS).forEach(function (wrapper) {
        // this will keep track of the scrollbar state for the iframe
        // underneath this wrapper
        var SCROLLBAR_VISIBLE = true;

        // hides scrollbar once its "pushed" outside of the box
        wrapper.style.overflow = "hidden";

        var iframe = wrapper.querySelector("iframe");

        // hide the scrollbar immediately by default
        if (SCROLLBAR_OFF_DEFAULT) {
            toggleIframeWidth(iframe, SCROLLBAR_VISIBLE);
            SCROLLBAR_VISIBLE = false;
        }

        // construct scrollbar fix button
        var button = constructToggleButton(wrapper);

        // and trigger iframe width adjustment and scrollbar state on click
        button.addEventListener("click", function () {
            toggleIframeWidth(iframe, SCROLLBAR_VISIBLE);
            SCROLLBAR_VISIBLE = !SCROLLBAR_VISIBLE;
        });
    });

    // toggles the width of a given iframe based on scrollbar visibility
    function toggleIframeWidth(iframe, visible) {
        var width = visible ? SCROLLBAR_WIDTH : -SCROLLBAR_WIDTH;
        iframe.width = (parseFloat(iframe.width) + width) + "px";
    }

    // will construct the scrollbar toggle button next to the settings
    // and orientation buttons
    function constructToggleButton(wrapper) {
        var button = document.createElement("div"),
            buttonIcon = document.createElement("span"),
            buttonWrapper = wrapper.querySelector(S_CONTROLS);

        button.title = "Toggle Scrollbar";
        button.className = C_BUTTON;
        button.style.marginLeft = "5px";
        buttonIcon.className = "fa fa-arrows-v c-device__button-icon " + C_ICON;
        button.appendChild(buttonIcon);
        buttonWrapper.appendChild(button);

        return button;
    }
})();