---
id: 6196d0cda039d026f7f78d1e
title: ในใใใ 22
challengeType: 0
dashedName: step-22
---
# --description--
Change the stack level of the `.back-mountain` element such that it is directly behind the `.left-mountain` element.
# --hints--
You should use the `z-index` property to change the stack level.
```js
assert.notEmpty(new __helpers.CSSHelp(document).getStyle('.back-mountain')?.zIndex);
```
You should set the `z-index` property to `1`.
```js
assert.equal(new __helpers.CSSHelp(document).getStyle('.back-mountain')?.zIndex, '1');
```
You should not change the `z-index` of the `.left-mountain` element.
```js
assert.equal(new __helpers.CSSHelp(document).getStyle('.left-mountain')?.zIndex, '2');
```
# --seed--
## --seed-contents--
```html
Penguin
```
```css
body {
background: linear-gradient(45deg, rgb(118, 201, 255), rgb(247, 255, 222));
margin: 0;
padding: 0;
width: 100%;
height: 100vh;
overflow: clip;
}
.left-mountain {
width: 300px;
height: 300px;
background: linear-gradient(rgb(203, 241, 228), rgb(80, 183, 255));
position: absolute;
transform: skew(0deg, 44deg);
z-index: 2;
margin-top: 100px;
}
--fcc-editable-region--
.back-mountain {
width: 300px;
height: 300px;
background: linear-gradient(rgb(203, 241, 228), rgb(47, 170, 255));
position: absolute;
}
--fcc-editable-region--
.penguin {
width: 300px;
height: 300px;
margin: auto;
margin-top: 75px;
}
.ground {
width: 100vw;
height: 400px;
background: linear-gradient(90deg, rgb(88, 175, 236), rgb(182, 255, 255));
z-index: 3;
position: absolute;
margin-top: -58px;
}
```