It also supports functional programming since functions Here is helper funktion to encode to base64url: You can use btoa()/atob() in browser, but some improvements required, as described here https://base64tool.com/uncaught-domexception-btoa-on-window/ and there https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/btoa for UTF strings support! forEach undefined Accessing style object(s) from the head section of the document: Accessing a specified element's style object: You can create a