What I've learned from each module:
- Adding a 'transitionend' listener instead of a timeout, because timout can get out of synch with the css transition
- transform origin css property used for rotation
- new CSS variables that can be updated with javascript
- data attributes, and using the dataset property from an event to get all the data attributes
- nothing new
- learned about flexbox, and event.propertyName.includes function
- adding an array as innerHtml, uses the join() method and automatically adds commas.
- the change method of an input only fires when loosing focus, not on every keystroke