The “Get a hint” button links to a 404 error page at the URL: https://guide.freecodecamp.org/certifications/responsive-web-design/basic-css/improve-compatibility-with-browser-fallbacks
Also, the following code is marked wrong when it is correct:
<style>
:root {
--red-color: red;
}
.red-box {
background: red;
background: var(--red-color, red);
height: 200px;
width:200px;
}
</style>
<div class="red-box"></div>
This change will result in a successful run. This is still technically correct but is now missing the best practices taught in the last lesson of accounting for variable errors.
<style>
:root {
--red-color: red;
}
.red-box {
background: red;
background: var(--red-color);
height: 200px;
width:200px;
}
</style>
<div class="red-box"></div>