istio.io/archive/v0.8/js/styleSwitcher.min.js

"use strict";function applyStyleSheet(e){var t,i;for(t=0;i=document.getElementsByTagName("link")[t];t++)-1!==i.getAttribute("rel").indexOf("style")&&i.getAttribute("title")&&(i.disabled=!0,i.getAttribute("title")===e&&(i.disabled=!1));var l=document.getElementById("light-theme-item");null!==l&&("light"===e?l.classList.add("active"):l.classList.remove("active")),null!==(l=document.getElementById("dark-theme-item"))&&("dark"===e?l.classList.add("active"):l.classList.remove("active"))}function getPreferredStyleSheet(){var e,t;for(e=0;t=document.getElementsByTagName("link")[e];e++)if(-1!==t.getAttribute("rel").indexOf("style")&&-1===t.getAttribute("rel").indexOf("alt")&&t.getAttribute("title"))return t.getAttribute("title");return null}function createCookie(e,t,i){if(i){var l=new Date;l.setTime(l.getTime()+24*i*60*60*1e3);var r="; expires="+l.toGMTString()}else r="";document.cookie=e+"="+t+r+"; path=/"}function readCookie(e){for(var t=e+"=",i=document.cookie.split(";"),l=0;l<i.length;l++){for(var r=i[l];" "===r.charAt(0);)r=r.substring(1,r.length);if(0===r.indexOf(t))return r.substring(t.length,r.length)}return null}function setActiveStyleSheet(e){applyStyleSheet(e),createCookie("style",e)}function loadActiveStyleSheet(){var e=readCookie("style");applyStyleSheet(null===e?getPreferredStyleSheet():e)}window.onload=function(e){loadActiveStyleSheet()},loadActiveStyleSheet();