istio.io/archive/v0.6/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 r=document.getElementsByTagName("body")[0];if(void 0!=r){var l=r.getAttribute("class").split(" ");for(t=0;t<l.length;t++)l[t].startsWith("theme-")&&(l[t]="theme-"+e);r.setAttribute("class",l.join(" "))}}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 r=new Date;r.setTime(r.getTime()+24*i*60*60*1e3);var l="; expires="+r.toGMTString()}else l="";document.cookie=e+"="+t+l+"; path=/"}function readCookie(e){for(var t=e+"=",i=document.cookie.split(";"),r=0;r<i.length;r++){for(var l=i[r];" "==l.charAt(0);)l=l.substring(1,l.length);if(0==l.indexOf(t))return l.substring(t.length,l.length)}}function setActiveStyleSheet(e){applyStyleSheet(e),createCookie("style",e)}function loadActiveStyleSheet(){var e=readCookie("style");applyStyleSheet(void 0==e?getPreferredStyleSheet():e)}window.onload=function(e){loadActiveStyleSheet()},loadActiveStyleSheet();