---
id: 5d822fd413a79914d39e98d1
title: Step 9
challengeType: 0
dashedName: step-9
---
# --description--
Give your background buildings element a `width` and `height` of `100%` to make it the full width and height of its parent, the `body`.
# --hints--
You should use the `background-buildings` class to select the correct element.
```js
assert.exists(new __helpers.CSSHelp(document).getStyle('.background-buildings'));
```
Your `.background-buildings` element should have a `width` of `100%`.
```js
assert.equal(new __helpers.CSSHelp(document).getStyle('.background-buildings')?.width, '100%');
```
Your `.background-buildings` element should have a `height` of `100%`.
```js
assert.equal(new __helpers.CSSHelp(document).getStyle('.background-buildings')?.height, '100%');
```
# --seed--
## --seed-contents--
```html
City Skyline
```
```css
* {
border: 1px solid black;
box-sizing: border-box;
}
body {
height: 100vh;
margin: 0;
overflow: hidden;
}
--fcc-editable-region--
--fcc-editable-region--
```