Improve Compatibility with Browser Fallbacks please help

Tell us what’s happening:
how can i write this down . the fall back background color to make it red. it still refuses to work

Your code so far

  :root {
    --red-color: red;

  .red-box {
    background: var(--red-skin);
    height: 200px;

<div class="red-box"></div>

**Link to the challenge:**

You misspelled the variable name, it’s not --red-skin.

ooooh thanks so much