Improve Compatibility with Browser Fallbacks issue

HTML-CSS
1

I dont understand How to solve this task? Can anyone help?

Your code so far


<style>
  :root {
    --red-color: red;
  }
  .red-box {
    
    background: var(--red-color,red);
    
    height: 200px;
    width:200px;
  }
</style>
<div class="red-box"></div>

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:64.0) Gecko/20100101 Firefox/64.0.

Link to the challenge:
https://learn.freecodecamp.org/responsive-web-design/basic-css/improve-compatibility-with-browser-fallbacks

2

They just ask you to write before the background declaration another background declaration with a different value.

This is just in case if the browser doesn’t understand css variables .

3

Got it! thanks to you