toggle-styles.js

(function() {
    'use strict';

    var attributeStorage = 'data-css-storage';
    var attributeDisabled = 'data-css-disabled';
    var elements = [];

    var disabled = areStylesDisabled();
    if (!disabled) {
        // disable styles
        elements = document.querySelectorAll('[style], link, style');

        [].slice.call(elements).forEach(function(el) {
            if (el.tagName === 'STYLE') {
                saveToStorage(el, el.innerHTML);
                el.innerHTML = '';
            } else if (el.tagName === 'LINK') {
                saveToStorage(el, '');
                el.disabled = true;
            } else {
                saveToStorage(el, el.style.cssText);
                el.style.cssText = '';
            }
        });
    } else {
        // re-enable styles
        elements = document.querySelectorAll('[' + attributeStorage + ']');

        [].slice.call(elements).forEach(function(el) {
            if (el.tagName === 'STYLE') {
                el.innerHTML = getFromStorage(el);
            } else if (el.tagName === 'LINK') {
                el.disabled = false;
            } else {
                el.style.cssText = getFromStorage(el);
            }
        });
    }

    function saveToStorage(el, data) {
        el.setAttribute(attributeStorage, data);
    }

    function getFromStorage(el) {
        var data = el.getAttribute(attributeStorage);
        el.removeAttribute(attributeStorage);

        return data;
    }

    function areStylesDisabled() {
        var el = document.body;

        var disabled = el.hasAttribute(attributeDisabled);
        if (disabled) {
            el.removeAttribute(attributeDisabled);
        } else {
            el.setAttribute(attributeDisabled, '');
        }

        return disabled;
    }

}());