What is the equivalent of the following jQuery animate in pure JavaScript?
Element.animate() function seems to be very simple and useful. But there are for now a lot of compatibility issues. You can read about it:
https://developer.mozilla.org/en-US/docs/Web/API/Element/animate
I would recommend to get used to requestAnmationFrame. It's compatible with all browsers and it is very powerful:
https://javascript.info/js-animation