I still can't understand this, even with the previous questions answered. I'm only 13 and my teacher is making our class do this, and I have a computer test about HTML and CSS coming up tomorrow!

Tell us what’s happening:

Your code so far

  :root {
    --red-color: red;
  .red-box {
<div class="red-box"></div>

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.119 Safari/537.36.

What exactly is your question? You have to add the red background as fallback?

No, not really, but anyway, I got it correct. Thanks for trying to help me!