---
id: 5d822fd413a79914d39e98d8
title: Part 16
challengeType: 0
dashedName: part-16
---

# --description--

It's that simple. Use the same variable as the `background-color` of the `bb1b`, `bb1c`, and `bb1d` classes to fill in the rest of the building.

# --hints--

test-text

```js
const bb1bStyle = code.match(/\.bb1b\s*{[\s\S]+?[^}]}/g)[0];
const bb1cStyle = code.match(/\.bb1c\s*{[\s\S]+?[^}]}/g)[0];
const bb1dStyle = code.match(/\.bb1d\s*{[\s\S]+?[^}]}/g)[0];
assert(
  /background-color\s*:\s*var\(\s*--building-color1\s*\)\s*(;|\s*})/g.test(
    bb1bStyle
  ) &&
    /background-color\s*:\s*var\(\s*--building-color1\s*\)\s*(;|\s*})/g.test(
      bb1cStyle
    ) &&
    /background-color\s*:\s*var\(\s*--building-color1\s*\)\s*(;|\s*})/g.test(
      bb1dStyle
    )
);
```

# --seed--

## --seed-contents--

```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%;
      }
  
      .bb1c {
        width: 90%;
        height: 10%;
      }

      .bb1d {
        width: 100%;
        height: 70%;
      }
    </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>
```

# --solutions--

```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>
```
