freeCodeCamp/guide/english/certifications/responsive-web-design/basic-css/change-a-variable-for-a-specific-area/index.md

---
title: Change a variable for a specific area
---
# Change a variable for a specific area

---
## Problem Explanation
Cascading CSS variables officially called custom properties are entities which behave similarly to traditional variables. In that variables allow for data to be stored and updated to reflect new values later. 

When maintaining complex CSS documents, it is not only beneficial to use CSS Variables but also smart.  When making future updates instead of searching potential hundreds of lines of code, one only needs to update the necessary CSS variable.

**Example Syntax:**

Declaring the variable: 

```css
--custom-name: value
```

Using the variable:

```css 
var(--custom-name)
```

---
## Solutions

<details><summary>Solution 1 (Click to Show/Hide)</summary>

We need to reassign the ```--penguin-belly``` variable to ```white``` in the ```penguin``` class:

```css
  .penguin {
    /* add code below */
    --penguin-belly: white;
    /* add code above */
    position: relative;
    margin: auto;
    display: block;
    margin-top: 5%;
    width: 300px;
    height: 300px;
  }
```

#### Relevant Links
1. [Visit MDN's Cascading CSS Variables page for more information.](https://developer.mozilla.org/en-US/docs/Web/CSS/Using_CSS_variables)
2. [Perna, Maria Antonietta. "A Practical Guide to CSS Variables (Custom Properties)" *sitepoint*. August 01, 2018. Accessed: October 5, 2018](https://www.sitepoint.com/practical-guide-css-variables-custom-properties/)
</details>