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Using Variables In CSS

· 3 min read
Parth Maheta

Unleashing the Power of CSS Variables

Cascading Style Sheets (CSS) have evolved over the years, and one of the game-changers introduced in CSS3 is the concept of CSS variables.

Also known as custom properties, CSS variables bring a new level of flexibility and efficiency to web development. In this article, we'll explore what CSS variables are, how they work, and why they are a valuable addition to your styling toolkit.

Understanding CSS Variables:

CSS variables allow developers to store and reuse values in a stylesheet. They are defined using the -- prefix followed by a user-defined name. For example:

:root {
--main-color: #3498db;

body {
background-color: var(--main-color);

In this example, --main-color is a CSS variable that stores the color #3498db. The var(--main-color) syntax is then used to apply this color to the background of the body element.

Benefits of CSS Variables:

  1. Maintainability: CSS variables promote maintainability by centralizing key values. If you need to change a color or a font across your entire website, you can simply update the variable, and the change will cascade throughout the stylesheet.

  2. Dynamic Changes: Unlike traditional constants in CSS, variables can be modified dynamically using JavaScript. This opens the door to creating dynamic and responsive designs without having to rewrite your entire stylesheet.

  3. Scoped Variables: CSS variables can be defined globally or scoped to specific elements. This allows for more granular control over styling, making it easier to manage styles in large projects.

  4. Conciseness: By using variables, CSS becomes more concise and readable. Instead of repeating the same values throughout your stylesheet, you can refer to variables, making your code cleaner and more maintainable.

Practical Examples:

Let's dive into a practical example to illustrate the power of CSS variables. Consider a scenario where you want to create a theme-switching feature on your website. With CSS variables, this becomes a breeze:

:root {
--main-background: #ffffff;
--main-text: #333333;

body {
background-color: var(--main-background);
color: var(--main-text);

.dark-theme {
--main-background: #222222;
--main-text: #ffffff;

By toggling a class like dark-theme on the body element, you can instantly transform the entire color scheme of your website.


CSS variables are a powerful addition to the web developer's arsenal. They enhance maintainability, enable dynamic changes, and contribute to more concise and readable stylesheets. As you explore the possibilities of CSS variables, you'll find that they empower you to create flexible, responsive, and easily maintainable designs. Incorporating CSS variables into your workflow is not just a trend – it's a valuable technique that enhances the efficiency and creativity of web development.