I knew a little, HTML, much less CSS and no JS when I started this course. I found this a great way to see how they all work together.
Here is my launch attempt: https://dancinggecko.github.io/js-rocket/rocket.html#
There's one issue I can't solve, but that is absolutely fine when I just call up the local files in Chrome. When using the link from github, the rocket doesn't come back to the start screen after it's launched. It's there every time from the local source.
Making the words disappear again: I tried hard to logic my way to finding an answer to this, but my code got out of shape. So... I used my new knowledge on hunting through the page code using the Developer Console and looked through some classmate's code. So, kudos to Richard Ziegler for helping me solve that one! :-)