Modern CSS Variables and Custom Properties

CSS Custom Properties, commonly known as CSS variables, have revolutionized how we write and maintain stylesheets. They provide a powerful way to create dynamic, themeable, and maintainable CSS with native browser support.

What Are CSS Custom Properties?

CSS Custom Properties are entities defined by CSS authors that contain specific values to be reused throughout a document. They are set using custom property notation and accessed using the var() function.

Declaring and Using CSS Variables

CSS variables are declared with a custom property name that begins with two dashes (--) and are assigned a value like any other CSS property. The :root pseudo-class is commonly used to declare global variables.

Advantages of CSS Variables

CSS variables offer numerous benefits including dynamic updates at runtime with JavaScript, scoping and inheritance, no build step required, and excellent DevTools support.

Creating Theme Systems

One of the most powerful uses of CSS variables is creating theme systems. By defining color schemes and design tokens as variables, you can create multiple themes that can be switched instantly.

Dynamic Variables with JavaScript

Unlike preprocessor variables, CSS custom properties can be manipulated with JavaScript, enabling truly dynamic styling for interactive themes and user customization options.

Conclusion

CSS Custom Properties are a powerful native feature that enables more maintainable, flexible, and dynamic stylesheets. Start incorporating CSS variables into your projects today!