CSS var

Introduction to CSS var()

The var() function in CSS is a powerful tool that allows developers to use custom properties (often referred to as CSS variables) throughout their stylesheets. These custom properties provide a way to store values that can be reused, making your CSS more maintainable and easier to read.

Custom properties are defined using the notation --variableName and can be accessed using the var() function.

Defining Custom Properties

To define a custom property, you declare it within a selector, typically the :root pseudo-class, which represents the document's root element. This makes the custom properties accessible throughout the document.

Here's an example of defining a custom property:

Using Custom Properties

Once you've defined a custom property, you can use it in your CSS by calling the var() function with the property's name. Here's how you can apply the previously defined custom properties:

Providing Fallback Values

One of the significant advantages of using var() is the ability to specify fallback values. A fallback value is used if the custom property is not defined or invalid. This is especially useful for ensuring compatibility across different browsers or in more complex stylesheets.

Here's an example of using a fallback value:

Benefits of Using CSS Variables

• Maintainability: Centralize CSS values for easier updates.
• Reusability: Use variables across different components and styles.
• Dynamic Styles: Change variables using JavaScript for dynamic styling.

Conclusion

CSS custom properties and the var() function offer a flexible and efficient way to manage styles. By utilizing these features, you can create more organized, maintainable, and adaptable stylesheets that can respond dynamically to changes and conditions.