Another way to do hover states, using JavaScript. Normally I'd prefer CSS `:hover` or similar, but I wanted a way to move a `.selected` class around the DOM.

hover.js

var hover = (function () {
	var previousTarget = null;

	return function (event) {
		var currentTarget = event.srcElement;

		if(currentTarget === previousTarget) return;

		if(previousTarget) previousTarget.classList.remove('selected');

		if(currentTarget.nodeName.toLowerCase() === 'button') currentTarget.classList.add( 'selected' );

		previousTarget = currentTarget;
	};
})();

document.addEventListener('mousemove', hover, false);