opacity: 0 to the very first state when nothing has happened yet, and then later on add a
expanded class when expanded, and
unexpanded class when unexpanded (for the de-animation).
Comments are welcome 😊 I still consider myself a front-end dev newbie so I need all the help I can get. I'm having a particularly hard time putting BEM into practice, but I tried with this one (did I even do it right?).
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