Help for fall back task

Tell us what’s happening:

Your code so far


:root {
  --red-color: red;
.red-box {

  background: var(--red-color);

  height: 200px;

<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/80.0.3987.116 Safari/537.36.

Challenge: Improve Compatibility with Browser Fallbacks

Link to the challenge:

A short explanation of what you’re having trouble with would be useful in getting people to reply to your post.

thanks to remind me. i have updated my problem again.

thanks i have completed it.