2018-09-30 23:01:58 +01:00
---
id: 5a9d7286424fe3d0e10cad13
title: Attach a Fallback value to a CSS Variable
challengeType: 0
videoUrl: 'https://scrimba.com/c/c6bDNfp'
2019-08-05 09:17:33 -07:00
forumTopicId: 301084
2021-01-13 03:31:00 +01:00
dashedName: attach-a-fallback-value-to-a-css-variable
2018-09-30 23:01:58 +01:00
---
2020-11-27 19:02:05 +01:00
# --description--
2020-07-13 18:58:50 +02:00
2018-09-30 23:01:58 +01:00
When using your variable as a CSS property value, you can attach a fallback value that your browser will revert to if the given variable is invalid.
2020-11-27 19:02:05 +01:00
**Note:** This fallback is not used to increase browser compatibility, and it will not work on IE browsers. Rather, it is used so that the browser has a color to display if it cannot find your variable.
2018-09-30 23:01:58 +01:00
Here's how you do it:
2019-05-14 01:11:58 -07:00
```css
background: var(--penguin-skin, black);
```
2021-02-01 11:56:07 -08:00
This will set background to `black` if your variable wasn't set. Note that this can be useful for debugging.
2018-09-30 23:01:58 +01:00
2020-11-27 19:02:05 +01:00
# --instructions--
2020-07-13 18:58:50 +02:00
2020-11-27 19:02:05 +01:00
It looks like there is a problem with the variables supplied to the `.penguin-top` and `.penguin-bottom` classes. Rather than fix the typo, add a fallback value of `black` to the `background` property of the `.penguin-top` and `.penguin-bottom` classes.
2018-09-30 23:01:58 +01:00
2020-11-27 19:02:05 +01:00
# --hints--
2020-07-13 18:58:50 +02:00
2020-11-27 19:02:05 +01:00
The fallback value of `black` should be used in the `background` property of the `penguin-top` class.
2018-09-30 23:01:58 +01:00
2020-11-27 19:02:05 +01:00
```js
assert(
code.match(
/.penguin-top\s*?{[\s\S]*background\s*?:\s*?var\(\s*?--pengiun-skin\s*?,\s*?black\s*?\)\s*?;[\s\S]*}[\s\S]*.penguin-bottom\s{/gi
)
);
2018-09-30 23:01:58 +01:00
```
2020-11-27 19:02:05 +01:00
The fallback value of `black` should be used in `background` property of the `penguin-bottom` class.
2018-09-30 23:01:58 +01:00
2020-11-27 19:02:05 +01:00
```js
assert(
code.match(
/.penguin-bottom\s*?{[\s\S]*background\s*?:\s*?var\(\s*?--pengiun-skin\s*?,\s*?black\s*?\)\s*?;[\s\S]*}/gi
)
);
```
2020-07-13 18:58:50 +02:00
2020-11-27 19:02:05 +01:00
# --seed--
2018-09-30 23:01:58 +01:00
2020-11-27 19:02:05 +01:00
## --seed-contents--
2018-09-30 23:01:58 +01:00
```html
< style >
.penguin {
--penguin-skin: black;
--penguin-belly: gray;
--penguin-beak: yellow;
position: relative;
margin: auto;
display: block;
margin-top: 5%;
width: 300px;
height: 300px;
}
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
.penguin-top {
top: 10%;
left: 25%;
2018-10-08 01:01:53 +01:00
2020-02-27 07:20:46 -08:00
/* Change code below this line */
2018-09-30 23:01:58 +01:00
background: var(--pengiun-skin);
2020-02-27 07:20:46 -08:00
/* Change code above this line */
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
width: 50%;
height: 45%;
border-radius: 70% 70% 60% 60%;
}
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
.penguin-bottom {
top: 40%;
left: 23.5%;
2018-10-08 01:01:53 +01:00
2020-02-27 07:20:46 -08:00
/* Change code below this line */
2018-09-30 23:01:58 +01:00
background: var(--pengiun-skin);
2020-02-27 07:20:46 -08:00
/* Change code above this line */
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
width: 53%;
height: 45%;
border-radius: 70% 70% 100% 100%;
}
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
.right-hand {
top: 0%;
left: -5%;
background: var(--penguin-skin, black);
width: 30%;
height: 60%;
border-radius: 30% 30% 120% 30%;
transform: rotate(45deg);
z-index: -1;
}
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
.left-hand {
top: 0%;
left: 75%;
background: var(--penguin-skin, black);
width: 30%;
height: 60%;
border-radius: 30% 30% 30% 120%;
transform: rotate(-45deg);
z-index: -1;
}
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
.right-cheek {
top: 15%;
left: 35%;
background: var(--penguin-belly, white);
width: 60%;
height: 70%;
border-radius: 70% 70% 60% 60%;
}
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
.left-cheek {
top: 15%;
left: 5%;
background: var(--penguin-belly, white);
width: 60%;
height: 70%;
border-radius: 70% 70% 60% 60%;
}
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
.belly {
top: 60%;
left: 2.5%;
background: var(--penguin-belly, white);
width: 95%;
height: 100%;
border-radius: 120% 120% 100% 100%;
}
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
.right-feet {
top: 85%;
left: 60%;
background: var(--penguin-beak, orange);
width: 15%;
height: 30%;
border-radius: 50% 50% 50% 50%;
transform: rotate(-80deg);
z-index: -2222;
}
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
.left-feet {
top: 85%;
left: 25%;
background: var(--penguin-beak, orange);
width: 15%;
height: 30%;
border-radius: 50% 50% 50% 50%;
transform: rotate(80deg);
z-index: -2222;
}
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
.right-eye {
top: 45%;
left: 60%;
background: black;
width: 15%;
height: 17%;
border-radius: 50%;
}
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
.left-eye {
top: 45%;
left: 25%;
background: black;
width: 15%;
height: 17%;
border-radius: 50%;
}
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
.sparkle {
top: 25%;
left: 15%;
background: white;
width: 35%;
height: 35%;
border-radius: 50%;
}
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
.blush-right {
top: 65%;
left: 15%;
background: pink;
width: 15%;
height: 10%;
border-radius: 50%;
}
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
.blush-left {
top: 65%;
left: 70%;
background: pink;
width: 15%;
height: 10%;
border-radius: 50%;
}
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
.beak-top {
top: 60%;
left: 40%;
background: var(--penguin-beak, orange);
width: 20%;
height: 10%;
border-radius: 50%;
}
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
.beak-bottom {
top: 65%;
left: 42%;
background: var(--penguin-beak, orange);
width: 16%;
height: 10%;
border-radius: 50%;
}
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
body {
2020-07-13 18:58:50 +02:00
background: #c6faf1 ;
2018-09-30 23:01:58 +01:00
}
2018-10-08 01:01:53 +01:00
2018-09-30 23:01:58 +01:00
.penguin * {
position: absolute;
}
< / style >
< div class = "penguin" >
< div class = "penguin-bottom" >
< div class = "right-hand" > < / div >
< div class = "left-hand" > < / div >
< div class = "right-feet" > < / div >
< div class = "left-feet" > < / div >
< / div >
< div class = "penguin-top" >
< div class = "right-cheek" > < / div >
< div class = "left-cheek" > < / div >
< div class = "belly" > < / div >
< div class = "right-eye" >
< div class = "sparkle" > < / div >
< / div >
< div class = "left-eye" >
< div class = "sparkle" > < / div >
< / div >
< div class = "blush-right" > < / div >
< div class = "blush-left" > < / div >
< div class = "beak-top" > < / div >
< div class = "beak-bottom" > < / div >
< / div >
< / div >
```
2020-11-27 19:02:05 +01:00
# --solutions--
2018-09-30 23:01:58 +01:00
2020-07-13 18:58:50 +02:00
```html
< style >
.penguin-top {
background: var(--pengiun-skin, black);
}
.penguin-bottom {
background: var(--pengiun-skin, black);
}
< / style >
2018-09-30 23:01:58 +01:00
```