All mouse events provide coordinates in two flavours: We already covered the difference between them in the chapter Coordinates. Events are actions that happen when a user interacts with the page - like clicking an element, typing in a field, or loading a page. Change color of a paragraph containing aligned equations. In order to animate these CSS Transform properties with JavaScript, we need to find the HTML element whose CSS properties we want to animate in the page DOM, and then find the specific CSS properties we want to change in the DOM node.