This code would be a bit shorter and simpler if it dropped support for old browsers (specifically, Internet Explorer). Some examples: The functions hasClass,

This code would be a bit shorter and simpler if it dropped support for old browsers (specifically, Internet Explorer). Some examples: The functions hasClass, addClass, and remClass could be replaced by Element.classList [0]. Another one is remEl, which can be replaced with a direct call to ChildNode.remove() [1]. I was going to give more examples, but I don't feel like rewriting the whole script. [0] https://developer.mozilla.org/en-US/docs/Web/API/Element/classList https://developer.mozilla.org/en-US/docs/Web/API/Element/cla... [1] https://developer.mozilla.org/en-US/docs/Web/API/ChildNode/remove https://developer.mozilla.org/en-US/docs/Web/API/ChildNode/r...