Help plz im stuck its hard for me

Tell us what’s happening:
Describe your issue in detail here.

  **Your code so far**

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

  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/96.0.4664.110 Safari/537.36

Challenge: Improve Compatibility with Browser Fallbacks

Link to the challenge:

Hello newtocodeing.
What is the hard part for you? It seems like you haven’t changed the default code. It basically asks you to include a background fallback set to red.
Hint: Try adding background: red; to the .red-box class.
Solution:

mod redacted solution

@ErFy

It is great that you solved the challenge, but instead of posting your full working solution, it is best to stay focused on answering the original poster’s question(s) and help guide them with hints and suggestions to solve their own issues with the challenge.

We are trying to cut back on the number of spoiler solutions found on the forum and instead focus on helping other campers with their questions and definitely not posting full working solutions.

You can post solutions that invite discussion (like asking how the solution works, or asking about certain parts of the solution). But please don’t just post your solution for the sake of sharing it.
If you post a full passing solution to a challenge and have questions about it, please surround it with [spoiler] and [/spoiler] tags on the line above and below your solution code.

That is understandable, but I posted a blurred solution so the OP can unblur it or just leave it to solve the challenge him/herself.

Please reread this portion
You can post solutions that invite discussion (like asking how the solution works, or asking about certain parts of the solution). But please don’t just post your solution for the sake of sharing it.
If you post a full passing solution to a challenge and have questions about it, please surround it with [spoiler] and [/spoiler] tags on the line above and below your solution code.

i figure it out by myself later on and thank for ur effort