---
id: 5d822fd413a79914d39e98e1
title: Part 25
challengeType: 0
isHidden: true
---
## Description
That one used the fallback value as well? I see the problem now! The variables you declared in `bb1` do not cascade to the `bb2` and `bb3` sibling elements. That's just how CSS works. Because of this, variables are often declared in the `:root` selector. This is the highest level selector in CSS; putting your variables there will make them usable everywhere. Add the `:root` selector to the top of your stylesheet and move all your variable declarations there.
## Instructions
## Tests
```yml
tests:
- text: test-text
testString: const bb1style = code.match(/\.bb1\s*{[\s\S]+?[^}]}/g)[0]; const rootStyle = code.match(/:root\s*{[\s\S]+?[^}]}/g)[0]; assert(/--building-color1\s*:\s*#aa80ff\s*(;|\s*})/g.test(rootStyle) && /--building-color2\s*:\s*#66cc99\s*(;|\s*})/g.test(rootStyle) && /--building-color3\s*:\s*#cc6699\s*(;|\s*})/g.test(rootStyle) && !/--building-color1\s*:\s*#aa80ff\s*(;|\s*})/g.test(bb1style) && !/--building-color2\s*:\s*#66cc99\s*(;|\s*})/g.test(bb1style) && !/--building-color3\s*:\s*#cc6699\s*(;|\s*})/g.test(bb1style));
```
## Challenge Seed
```html
freeCodeCamp Skyline Project
```