---
id: 5d822fd413a79914d39e98e9
title: Step 33
challengeType: 0
dashedName: step-33
---
# --description--
I see some code that can be optimized. Move the `position` and `top` properties and values from `.foreground-buildings` to `.background-buildings`. Then select both `.background-buildings` and `.foreground-buildings` there, effectively applying those styles to both of the elements. You can use a comma (`,`) to separate selectors like this: `selector1, selector2`.
# --hints--
You should not remove the `.foreground-buildings` declaration.
```js
assert.exists(new __helpers.CSSHelp(document).getStyle('.foreground-buildings'));
```
You should remove the `position` property from `.foreground-buildings`.
```js
assert.isEmpty(new __helpers.CSSHelp(document).getStyle('.foreground-buildings')?.position);
```
You should remove the `top` property from `.foreground-buildings`.
```js
assert.isEmpty(new __helpers.CSSHelp(document).getStyle('.foreground-buildings')?.top);
```
You should add the `position` property of `absolute` to `.background-buildings, foreground-buildings`.
```js
function eitherOr() {
const a = new __helpers.CSSHelp(document)
return a.getStyle('.background-buildings, .foreground-buildings') ?? a.getStyle('.foreground-buildings, .background-buildings');
}
assert.equal(eitherOr()?.position, 'absolute');
```
You should add the `top` property of `0` to `.background-buildings, foreground-buildings`.
```js
function eitherOr() {
const a = new __helpers.CSSHelp(document)
return a.getStyle('.background-buildings, .foreground-buildings') ?? a.getStyle('.foreground-buildings, .background-buildings');
}
assert.equal(eitherOr()?.top, '0px');
```
You should use a comma to use both `.foreground-buildings` and `.background-buildings` selectors in the same style declaration.
```js
function eitherOr() {
const a = new __helpers.CSSHelp(document)
return a.getStyle('.background-buildings, .foreground-buildings') ?? a.getStyle('.foreground-buildings, .background-buildings');
}
assert.exists(eitherOr());
```
# --seed--
## --seed-contents--
```html
City Skyline