How to add another fallback background if the actual from a class its been used

Tell us what’s happening:
how can I add another background, if it looks like the actual background color its been used it

It looks like a variable is being used to set the background color of the .red-box class. Let’s improve our browser compatibility by adding another background declaration right before the existing declaration and set its value to red .

  **Your code so far**

<style>
:root {
  --red-color: red;
  
}
.red-box {

  background: var(--red-color);
    color: red;  
    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/101.0.4951.64 Safari/537.36 Edg/101.0.1210.53

Challenge: Improve Compatibility with Browser Fallbacks

Link to the challenge:

It wants you to add a background property with the value of red just before the existing background property.