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								---
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								id: 5d822fd413a79914d39e98d9
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								title: Part 17
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								challengeType: 0
							 
						 
					
						
							
								
									
										
										
										
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								dashedName: part-17
							 
						 
					
						
							
								
									
										
										
										
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								---
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								# --description--
  
						 
					
						
							
								
									
										
										
										
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								I don't really like that color. Change the value of your variable from `#999`  to `#aa80ff`  and you can see how it gets applied everywhere you used the variable. This is the main advantage of using variables, being able to quickly change many values in your stylesheet by just changing the value of a variable.
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								# --hints--
  
						 
					
						
							
								
									
										
										
										
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								test-text
							 
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								const bb1style = code.match(/\.bb1\s*{[\s\S]+?[^}]}/g)[0];
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								assert(/--building-color1\s*:\s*#aa80ff \s*(;|\s*})/g.test(bb1style));
							 
						 
					
						
							
								
									
										
										
										
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								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								# --seed--
  
						 
					
						
							
								
									
										
										
										
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								## --seed-contents--
  
						 
					
						
							
								
									
										
										
										
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								```html
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								<!DOCTYPE html>  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								< html >      
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  < head > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    < title > freeCodeCamp Skyline Project< / title > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    < style > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      *  {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        border: 1px solid black;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        box-sizing: border-box;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      }
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      body {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        height: 100vh;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        margin: 0;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        overflow: hidden;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      }
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      .background-buildings {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        width: 100%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        height: 100%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      }
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      .bb1 {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        width: 10%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        height: 70%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        display: flex;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        flex-direction: column;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        align-items: center;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        --building-color1: #999 ;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      }
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      .bb1a {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        width: 70%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        height: 10%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        background-color: var(--building-color1);
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      }
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      .bb1b {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        width: 80%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        height: 10%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        background-color: var(--building-color1);
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      }
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      .bb1c {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        width: 90%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        height: 10%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        background-color: var(--building-color1);
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      }
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      .bb1d {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        width: 100%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        height: 70%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        background-color: var(--building-color1);
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      }
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    < / style > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  < / head > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  < body > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    < div  class = "background-buildings" > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      < div  class = "bb1" > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        < div  class = "bb1a" > < / div > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        < div  class = "bb1b" > < / div > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        < div  class = "bb1c" > < / div > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        < div  class = "bb1d" > < / div > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      < / div > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    < / div > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  < / body > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								< / html >  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								# --solutions--
  
						 
					
						
							
								
									
										
										
										
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								```html
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								<!DOCTYPE html>  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								< html >      
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  < head > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    < title > freeCodeCamp Skyline Project< / title > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    < style > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      *  {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        border: 1px solid black;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        box-sizing: border-box;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      }
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      body {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        height: 100vh;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        margin: 0;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        overflow: hidden;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      }
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      .background-buildings {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        width: 100%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        height: 100%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      }
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      .bb1 {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        width: 10%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        height: 70%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        display: flex;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        flex-direction: column;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        align-items: center;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        --building-color1: #aa80ff ;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      }
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      .bb1a {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        width: 70%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        height: 10%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        background-color: var(--building-color1);
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      }
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      .bb1b {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        width: 80%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        height: 10%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        background-color: var(--building-color1);
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      }
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      .bb1c {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        width: 90%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        height: 10%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        background-color: var(--building-color1);
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      }
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      .bb1d {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        width: 100%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        height: 70%;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        background-color: var(--building-color1);
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      }
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    < / style > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  < / head > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  < body > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    < div  class = "background-buildings" > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      < div  class = "bb1" > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        < div  class = "bb1a" > < / div > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        < div  class = "bb1b" > < / div > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        < div  class = "bb1c" > < / div > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        < div  class = "bb1d" > < / div > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      < / div > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    < / div > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  < / body > 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								< / html >  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```