Dúvida com variável

Tell us what’s happening:

  **Your code so far**

<style>
:root {
  --red-color: red;
}
.red-box {
  background: red;
  background: var(--red-color);
  height: 200px;
  width:200px;
}
</style>
<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/89.0.4389.114 Safari/537.36.
Porque eu devo colocar uma lista antes da variável e não dentro dela?

Challenge: Improve Compatibility with Browser Fallbacks

Link to the challenge:

Hi @nycole.xavierr !

Welcome to the forum!

The code you have shared works on my end. Please ensure that you have disabled any extensions that interface with the freeCodeCamp website (such as Dark Mode and Ad Blocker), and set your browser zoom level to 100%. Both of these factors can cause tests to fail erroneously.

You might also try another browser that is up to date and uses no extensions.

I am using google chrome without extensions and it works for me.