How do I Improve Compatibility with Browser Fallbacks

Tell us what’s happening:

Your code so far

  :root {
    --red-color: red;
  .red-box {
    background: var(--red-color, red);
    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/76.0.3809.100 Safari/537.36.

Link to the challenge:

Let’s improve our browser compatibility by adding another background declaration right before the existing declaration and set its value to red.

When a browser parses your code, it reads top to bottom. If it doesn’t understand a property, it will simply ignore it. If it does understand both properties, it will use the last one it reads. This is why it’s important to always put newer properties last.